VIO Commands

VIO Server Commands

lsdev –virtual (list all virtual devices on VIO server partitions)
lsmap –all (lists mapping between physical and logical devices)
oem_setup_env (change to OEM [AIX] environment on VIO server)

Create Shared Ethernet Adapter (SEA) on VIO Server

mkvdev –sea{physical adapt} –vadapter {virtual eth adapt} –default {dflt virtual adapt} –defaultid {dflt vlan ID}
SEA Failover
ent0 – GigE adapter
ent1 – Virt Eth VLAN1 (Defined with a priority in the partition profile)
ent2 – Virt Eth VLAN 99 (Control)
mkvdev –sea ent0 –vadapter ent1 –default ent1 –defaultid 1 –attr ha_mode=auto ctl_chan=ent2
(Creates ent3 as the Shared Ethernet Adapter)

Create Virtual Storage Device Mapping

mkvdev –vdev {LV or hdisk} –vadapter {vhost adapt} –dev {virt dev name}
Sharing a Single SAN LUN from Two VIO Servers to a Single VIO Client LPAR
hdisk = SAN LUN (on vioa server)
hdisk4 = SAN LUN (on viob, same LUN as vioa)
chdev –dev hdisk3 –attr reserve_policy=no_reserve (from vioa to prevent a reserve on the disk)
chdev –dev hdisk4 –attr reserve_policy=no_reserve (from viob to prevent a reserve on the disk)
mkvdev –vdev hdisk3 –vadapter vhost0 –dev hdisk3_v (from vioa)
mkvdev –vdev hdisk4 –vadapter vhost0 –dev hdisk4_v (from viob)
VIO Client would see a single LUN with two paths.
spath –l hdiskx (where hdiskx is the newly discovered disk)
This will show two paths, one down vscsi0 and the other down vscsi1.

VIO command from HMC
#viosvrcmd -m -p -c "lsmap -all

(this works only with IBM VIO Server)

see man viosvrcmd for more information

VIO Server Installation & Configuration

IBM Virtual I/O Server
The Virtual I/O Server is part of the IBM eServer p5 Advanced Power Virtualization hardware feature. Virtual I/O Server allows sharing of physical resources between LPARs including virtual SCSI and virtual networking. This allows more efficient utilization of physical resources through sharing between LPARs and facilitates server consolidation.

Installation
You have two options to install the AIX-based VIO Server:
1. Install from CD
2. Install from network via an AIX NIM-Server

Installation method
#1 is probably the more frequently used method in a pure Linux environment as installation method #2 requires the presence of an AIX NIM (Network Installation Management) server. Both methods differ only in the initial boot step and are then the same. They both lead to the following installation screen:

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------------------------------------------------------------------------------- Welcome to the Virtual I/O Server. boot image timestamp: 10:22 03/23 The current time and date: 17:23:47 08/10/2005 number of processors: 1 size of memory: 2048MB boot device: /pci@800000020000002/pci@2,3/ide@1/disk@0:\ppc\chrp\bootfile.exeSPLPAR info: entitled_capacity: 50 platcpus_active: 2This system is SMT enabled: smt_status: 00000007; smt_threads: 2 kernel size: 10481246; 32 bit kernel
-------------------------------------------------------------------------------




The next step then is to define the system console. After some time you should see the following screen:


******* Please define the System Console. *******Type a 1 and press Enter to use this terminal as the system console.


Then Choose language of installation


>>> 1 Type 1 and press Enter to have English during install.


This is the main installation menu of the AIX-based VIO-Server:



Welcome to Base Operating System
Installation and Maintenance
Type the number of your choice and press Enter. Choice is indicated by >>>.>>>

1 Start Install Now with Default Settings
2 Change/Show Installation Settings and Install
3 Start Maintenance Mode for System Recovery

88 Help ? 99 Previous Menu

>>> Choice [1]:


Select Hard disk where you need to install VIO base operating system as we do in AIX Base operating system.


Once the installation is over. You will get login Prompt similar to AIX server.

VIO server is nothing but AIX on top of that Virtualisation software loaded on it. Generally on VIO server we do not host any application. Its basically used for sharing I/O resources ( DISK & Network ) to the client LPAR hosted in same Physical server.


Initial setup
After the reboot you are presented with the VIO-Server login prompt. You can't login as user root as you have to use the special user id padmin. No initial default password is set. Immediately after login you are forced to set a new password.


Before you can do anything you have to accept the I/O Server license.
This is done with the license command

#license -accept

Once you are logged in as user padmin you find yourself in a restricted Korn shell with only a limited set of commands. You can see all available commands with the command help. All these commands are shell aliases to a single SUID-binary called ioscli which is located in the directory /usr/ios/cli/bin. If you are familiar with AIX you will recognize most commands but most command line parameters differ from the AIX versions.
As there are no man pages available you can see all options for each command separately by issueing the command help . Here is an example for the command lsmap:

$ help lsmap
Usage: lsmap {-vadapter ServerVirtualAdapter -plc PhysicalLocationCode
-all}
[-net] [-fmt delimiter]
Displays the mapping between physical and virtual devices.
-all Displays mapping for all the server virtual adapter
devices.
-vadapter Specifies the server virtual adapter device
by device name.
-plc Specifies the server virtual adapter device
by physical location code.
-net Specifies supplied device is a virtual server
Ethernet adapter.
-fmt Divides output by a user-specified delimiter.



A very important command is oem_setup_env which gives you access to the regular AIX command line interface. This is provided solely for the installation of OEM device drivers


Virtual SCSI setup

To map a LV
# mkvg: creates the volume group, where a new LV will be created using the mklv command
# lsdev: shows the virtual SCSI server adapters that could be used for mapping with the LV
# mkvdev: maps the virtual SCSI server adapter to the LV
# lsmap -all: shows the mapping information

To map a physical disk
# lsdev: shows the virtual SCSI server adapters that could be used for mapping with a physical disk
# mkvdev: maps the virtual SCSI server adapter to a physical disk
# lsmap -all: shows the mapping information

Client partition commands

No commands needed, the Linux kernel is notified immediately

Create new volume group datavg with member disk hdisk1
# mkvg -vg datavg hdisk1

Create new logical volume vdisk0 in volume group
# mklv -lv vdisk0 datavg 10G

Maps the virtual SCSI server adapter to the logical volume
# mkvdev -vdev vdisk0 -vadapter vhost0

Display the mapping information
#lsmap -all

Virtual Ethernet setup

To list all virtual and physical adapters use the lsdev -type adapter command.

$ lsdev -type adapter

name status description
ent0 Available 2-Port 10/100/1000 Base-TX PCI-X Adapter (14108902)
ent1 Available 2-Port 10/100/1000 Base-TX PCI-X Adapter (14108902)
ent2 Available Virtual I/O Ethernet Adapter (l-lan)
ide0 Available ATA/IDE Controller Device
sisscsia0 Available PCI-X Dual Channel Ultra320 SCSI Adapter
vhost0 Available Virtual SCSI Server Adapter
vhost1 Available Virtual SCSI Server Adapter
vhost2 Available Virtual SCSI Server Adapter
vhost3 Available Virtual SCSI Server Adapter
vsa0 Available LPAR Virtual Serial Adapter

Choose the virtual Ethernet adapter we want to map to the physical Ethernet adapter.

$ lsdev -virtualname status description
ent2 Available Virtual I/O Ethernet Adapter (l-lan)
vhost0 Available Virtual SCSI Server Adapter
vhost1 Available Virtual SCSI Server Adapter
vhost2 Available Virtual SCSI Server Adapter
vhost3 Available Virtual SCSI Server Adapter
vsa0 Available LPAR Virtual Serial Adapter

The command mkvdev maps a physical adapter to a virtual adapter, creates a layer 2 network bridge and defines the default virtual adapter with its default VLAN ID. It creates a new Ethernet interface, e.g., ent3.
Make sure the physical and virtual interfaces are unconfigured (down or detached).

Scenario A (one VIO server)
Create a shared ethernet adapter ent3 with a physical one (ent0) and a virtual one (ent2) with PVID 1:

$ mkvdev -sea ent0 -vadapter ent2 -default ent2 -defaultid 1
ent3 Available
en3
et3

This has created a new shared ethernet adapter ent3 (you can verify that with the lsdev command). Now configure the TCP/IP settings for this new shared ethernet adapter (ent3). Please note that you have to specify the interface (en3) and not the adapter (ent3).

$ mktcpip -hostname op710-1-vio -inetaddr 9.156.175.231 -interface en3 -netmask 255.255.255.0 -gateway 9.156.175.1 -nsrvaddr 9.64.163.21 -nsrvdomain ibm.com

Scenario B (two VIO servers)
Create a shared ethernet adapter ent3 with a physical one (ent0) and a virtual one (ent2) with PVID 1:

$ mkvdev -sea ent0 -vadapter ent2 -default ent2 -defaultid 1


Configure the TCP/IP settings for the new shared ethernet adapter (ent3):

$mktcpip -hostname op710-1-vio -inetaddr 9.156.175.231 -interface en3 -netmask 255.255.255.0 -gateway 9.156.175.1 -nsrvaddr 9.64.163.21 -nsrvdomain ibm.com

Client partition commands
No new commands needed just the typical TCP/IP configuration is done on the virtual Ethernet interface that it is defined in the client partition profile on the HMC

Creating LPAR from command line from HMC

Creating LPAR from command line from HMC

Create new LPAR using command line

mksyscfg -r lpar -m MACHINE -i name=LPARNAME, profile_name=normal, lpar_env=aixlinux, shared_proc_pool_util_auth=1,min_mem=512, desired_mem=2048, max_mem=4096, proc_mode=shared, min_proc_units=0.2, desired_proc_units=0.5,max_proc_units=2.0, min_procs=1, desired_procs=2, max_procs=2, sharing_mode=uncap, uncap_weight=128,boot_mode=norm, conn_monitoring=1, shared_proc_pool_util_auth=1


Note :- Use man mksyscfg command for all flag information.

Onother method of creating LPAR through configuration file we need to create more than one lPAR at same time

Here is an example for 2 LPARs, each definition starting at new line:

name=LPAR1,profile_name=normal,lpar_env=aixlinux,all_resources=0,min_mem=1024,desired_mem=9216,max_mem=9216,proc_mode=shared,min_proc_units=0.3,desired_proc_units=1.0,max_proc_units=3.0,min_procs=1,desired_procs=3,max_procs=3,sharing_mode=uncap,uncap_weight=128,lpar_io_pool_ids=none,max_virtual_slots=10,"virtual_scsi_adapters=6/client/4/vio1a/11/1,7/client/9/vio2a/11/1","virtual_eth_adapters=4/0/3//0/1,5/0/4//0/1",boot_mode=norm,conn_monitoring=1,auto_start=0,power_ctrl_lpar_ids=none,work_group_id=none,shared_proc_pool_util_auth=1
name=LPAR2,profile_name=normal,lpar_env=aixlinux,all_resources=0,min_mem=1024,desired_mem=9216,max_mem=9216,proc_mode=shared,min_proc_units=0.3,desired_proc_units=1.0,max_proc_units=3.0,min_procs=1,desired_procs=3,max_procs=3,sharing_mode=uncap,uncap_weight=128,lpar_io_pool_ids=none,max_virtual_slots=10,"virtual_scsi_adapters=6/client/4/vio1a/12/1,7/client/9/vio2a/12/1","virtual_eth_adapters=4/0/3//0/1,5/0/4//0/1",boot_mode=norm,conn_monitoring=1,auto_start=0,power_ctrl_lpar_ids=none,work_group_id=none,shared_proc_pool_util_auth=1

Copy this file to HMC and run:

mksyscfg -r lpar -m SERVERNAME -f /tmp/profiles.txt

where profiles.txt contains all LPAR informations as mentioned above.

To change setting of your Lpar use chsyscfg command as mentioned below.

Virtual scsi creation & Mapping Slots
#chsyscfg -m Server-9117-MMA-SNXXXXX -r prof -i 'name=server_name,lpar_id=xx,"virtual_scsi_adapters=301/client/4/vio01_server/301/0,303/client/4/vio02/303/0,305/client/4/vio01_server/305/0,307/client/4/vio02_server/307/0"'

IN Above mentioned command we are creating Virtual scsi adapter for client LPAR & doing Slot mapping with VIO servers. In above scenario there is two VIO servers for redundancy.


Slot Mapping

Vio01_server ( VSCSI server slot) Client ( Vscsi client Slot)
Slot 301 Slot 301
Slot 303 Slot 303

VIO02_server (VSCSI sever Slot) Client ( VSCSI client Slot)
Slot 305 Slot 305
Slot 307 Slot 307


These Slot are mapped in such a way if Any disk or logical volume are mapped to Virtuals scsi adapter through VIO command "mkvdev".

Syntax for Virtual scsi adapter


virtual-slot-number/client-or-server/supports-HMC/remote-lpar-ID/remote-lpar-name/remote-slot-number/is-required


As in command above mentioned command mksyscfg "virtual_scsi_adapters=301/client/4/vio01_server/301/0"

means

301 - virtual-slot-number
client-or-server - client (Aix_client)
4 -- Partiotion Id ov VIO_01 server (remote-lpar-ID)
vio01_server - remote-lpar-name
301 -- remote-slot-number (VIO server_slot means virtual server scsi slot)
1 -- Required slot in LPAR ( It cannot be removed from DLPAR operations )
0 --means desired ( it can be removed by DLPAR operations)


To add Virtual ethernet adapter & slot mapping for above created profile

#chsyscfg -m Server-9117-MMA-SNxxxxx -r prof -i 'name=server_name,lpar_id=xx,"virtual_eth_adapters=596/1/596//0/1,506/1/506//0/1,"'

Syntax for Virtual ethernet adapter


slot_number/is_ieee/port_vlan_id/"additional_vlan_id,additional_vlan_id"/is_trunk(number=priority)/is_required

means

So the adapter with this setting 596/1/596//0/1 would say it is in slot_number 596, Its is ieee, the port_vlan_id is 1, it has no VLAN id assigned, It is not a trunk adapter and it is required.

Listing LPAR information from HMC command line interface

Listing LPAR information from HMC command line interface

To list managed system (CEC) managed by HMC

# lssyscfg -r sys -F name

To list number of LPAR defined on the Managed system (CEC)

# lssyscfg -m SYSTEM(CEC) -r lpar -F name,lpar_id,state

To list LPAR created in your system use lsyscfg command as mentioned below.

# lssyscfg -r prof -m SYSTEM(CEC) --filter "lpar_ids=X, profiles_names=normal"

Flags

m-> Managed System name
lpar_ids -> Lpar ID (numeric Id for each LPAR created in the Managed system (CEC)
profile_name -> To choose profile of LPAR


To start console of LPAR from HMC

# mkvterm -m SYSTEM(CEC) --id X

m- > managed system (ex -p5-570_xyz)
id - > LPAR ID

To finish a VTERM, simply press ~ followed by a dot .!

To disconnect console of LPAR from HMC

# rmvterm -m SYSTEM(CEC) --id x

To access LPAR console for diffrent Managed system from HMC

#vtmenu


Activating Partition

hscroot@hmc-570:~> lssyscfg -m Server-9110-510-SN100xxx -r lpar -F name,lpar_id,state,default_profile VIOS1.3-FP8.0,1,Running,default linux_test,2,Not Activated,client_default hscroot@hmc-570:~> chsysstate -m Server-9110-510-SN100xxxx -r lpar -o on -b norm --id 2 -f client_default

The above example would boot the partition in normal mode. To boot it into SMS menu use -b sms and to boot it to the OpenFirmware prompt use -b of.

To restart a partition the chsysstate command would look like this:

hscroot@hmc-570:~> chsysstate -m Server-9110-510-SN100xxxx -r lpar --id 2 -o shutdown --immed --restart

And to turn it off - if anything else fails - use this:
hscroot@hmc-570:~> chsysstate -m Server-9110-510-SN100xxxx -r lpar --id 2 -o shutdown --immed
hscroot@hmc-570:~> lssyscfg -m Server-9110-510-SN100xxxx -r lpar -F name,lpar_id,state
VIOS1.3-FP8.0,1,Running
linux_test,2,Shutting Down

Deleting Partition

hscroot@hmc-570:~> lssyscfg -m Server-9110-510-SN100xxxx -r lpar -F name,lpar_id
VIOS1.3-FP8.0,1
linux_test,2
hscroot@hmc-570:~> rmsyscfg -m Server-9110-510-SN100xxxx -r lpar --id 2
hscroot@hmc-570:~> lssyscfg -m Server-9110-510-SN100xxxx -r lpar -F name,lpar_id
VIOS1.3-FP8.0,1

Enabling the Advanced POWER Virtualization Feature

Enabling the Advanced POWER Virtualization Feature

Enabling the Advanced POWER Virtualization Feature

Before we could use the virtual I/O, we had to determine whether the machine was enabled to use the feature. To do this, we right-clicked on the name of the target server in the HMC’s ‘Server and Partition’ view and looked at that server’s properties. Figure 4 shows it did not have the feature enabled.

Users can enable this feature by obtaining a key code from their IBM sales representative using information that the HMC gathers about their machine when the user navigates to Show Code Information in the HMC. Figure 5 shows how to navigate there as well as how to get to the HMC dialog box used to enter the activation code which renders the system VIO-capable. We obtained an access code and entered it in the dialog box in Figure

VIO server setup example

VIO server setup example

Virtual I/O Example
A user who currently runs applications on a POWER4 system may want to upgrade to a POWER5 system running AIX 5.3 in order to take advantage of virtual I/O. If so, do these three things:
y Create a Virtual I/O Server. y Add virtual LANs. y Define virtual SCSI devices.
In our example, we had an IBM eServer p5 550 Express with four CPUs that was running one AIX 5.3 database server LPAR, and we needed to create a second application server LPAR that uses a virtual SCSI disk as its boot disk. We wanted to share one Ethernet adapter between the database and application server LPARs and use this shared adapter to access an external network. Finally, we needed a private network between the two LPARs and we decided to implement it using virtual Ethernet devices (see Figure 3). We followed these steps to set up our system:

1. Enabled the Advanced POWER Virtualization feature.

2.Installed the Virtual I/

Virtual I/O Server installation overview

Virtual I/O Server installation overview

The Virtual I/O Server The Virtual I/O Server is a dedicated partition that runs a special operating system called IOS. This special type of partition has physical resources assigned to it in its HMC profile. The administrator issues server partition IOS commands to create virtual resources which present virtual LAN, virtual SCSI adapters, and virtual disk drives client partitions. The client partition’s operating systems recognize these resources as physical devices. The Virtual I/O Server is responsible for managing the interaction between the client LPAR and the physical device supporting the virtualized service. Once the administrator logs in to the Virtual I/O Server as the user padmin, he or she has access to a restricted Korn shell session. The administrator uses IOS commands to create, change, and remove these physical and virtual devices as well as to configure and manage the VIO server. Executing the help command on the VIO server command line lists the commands that are available in padmin’s restricted Korn Shell session

Virtual I/O Server installation

VIO Server code is packaged and shipped as an AIX mksysb image
on a VIO DVD

Installation methods
– DVD install
– HMC install - Open rshterm and type “installios”; follow the
prompts
– Network Installation Manager (NIM)

VIO Server can support multiple client types
– AIX 5.3
– SUSE Linux Enterprise Server 9 or 10 for POWER
– Red Hat Enterprise Linux AS for POWER Version 3 and 4


Virtual I/O Server Administration

The VIO server uses a command line interface running in a restricted shell
– no smitty or GUI

There is no root login on the VIO Server

A special user – padmin – executes VIO server commands

First login after install, user padmin is prompted to change password

After that, padmin runs the command “license –accept”

Slightly modified commands are used for managing devices, networks,
code installation and maintenance, etc.

The padmin user can start a root AIX shell for setting up third-party
devices using the command “oem_setup_env”

We can get all commands by executing help on padmin user id

$ help
Install Commands
Physical Volume Commands
Security Commands
updateios
lspv
lsgcl
lssw
migratepv
cleargcl
ioslevel
lsfailedlogin
remote_management
Logical Volume Command
oem_setup_env
lslv
UserID Commands
oem_platform_level
mklv
mkuser
license
extendlv
rmuser
rmlv
lsuser
LAN Commands
mklvcopy
passwd
mktcpip
rmlvcopy
chuser
hostname
cfglnagg
netstat
Volume Group Commands
Maintenance Commands
entstat
lsvg
chlang
cfgnamesrv
mkvg
diagmenu
traceroute
chvg
shutdown
ping
extendvg
fsck
optimizenet
reducevg
backupios
lsnetsvc
mirrorios
savevgstruct
unmirrorios
restorevgstruct
Device Commands
activatevg
starttrace
mkvdev
deactivatevg
stoptrace
lsdev
importvg
cattracerpt
lsmap
exportvg
bootlist
chdev
syncvg
snap
rmdev
startsysdump

cfgdev
topas
mkpath
mount
chpath
unmount
lspath
showmount
rmpath
startnetsvc
errlog
stopnetsvc

Virtual I/O Server Overview

Virtual I/O Server Overview

What is Advanced POWER Virtualization (APV)

APV – the hardware feature code for POWER5 servers that enables:
– Micro-partitioning – fractional CPU entitlements from a shared pool of
processors, beginning at one-tenth of a CPU
– Partition Load Manager (PLM) – a policy-based, dynamic CPU and
memory reallocation tool
– Physical disks can be shared as virtual disks to client partitions
– Shared Ethernet Adapter (SEA) – A physical adapter or EtherChannel in
a VIO Server can be shared by client partitions. Clients use virtual
Ethernet adapters

Virtual Ethernet – a LPAR-to-LPAR Virtual LAN within a POWER5 Server
– Does not require the APV feature code


Why Virtual I/O Server?

POWER5 systems will support more partitions than physical I/O slots
available
– Each partition still requires a boot disk and network connection, but
now they can be virtual instead of physical

VIO Server allows partitions to share disk and network adapter resources
– The Fibre Channel or SCSI controllers in the VIO Server can be
accessed using Virtual SCSI controllers in the clients
– A Shared Ethernet Adapter in the VIO Server can be a layer 2 bridge
for virtual Ethernet adapters in the clients

The VIO Server further enables on demand computing and server
consolidation



Virtualizing I/O saves:
– Gbit Ethernet Adapters
– 2 Gbit Fibre Channel Adapters
– PCI slots
– Eventually, IO drawers
– Server frames?
– Floor space?
– Electric, HVAC?
– Ethernet switch ports
– Fibre channel switch ports
– Logistics, scheduling, delays of physical Ethernet, SAN attach

Some servers run 90% utilization all the time – everyone knows which
ones.

Average utilization in the UNIX server farm is closer to 25%. They don’t
all maximize their use of dedicated I/O devices

VIO is departure from “new project, new chassis” mindset


Virtual I/O Server Characteristics


Requires AIX 5.3 and POWER5 hardware with APV feature

Installed as a special purpose, AIX-based logical partition

Uses a subset of the AIX Logical Volume Manager and attaches
to traditional storage subsystems

Inter-partition communication (client-server model) provided via
the POWER Hypervisor

Clients “see” virtual disks as traditional AIX SCSI hdisks, although
they may be a physical disk or logical volume on the VIO Server

One physical disk on a VIO server can provide logical volumes for
several client partitions


Virtual Ethernet

Virtual Ethernet
– Enable inter-lpar communications without a physical adapter
– IEEE-compliant Ethernet programming model
– Implemented through inter-partition, in-memory communication

VLAN splits up groups of network users on a physical network onto
segments of logical networks

Virtual switch provides support for multiple (up to 4K) VLANs
– Each partition can connect to multiple networks, through one or more adapters
– VIO server can add VLAN ID tag to the Ethernet frame as appropriate.
Ethernet switch restricts frames to ports that are authorized to receive frames
with specific VLAN ID

Virtual network can connect to physical network through “routing"
partitions – generally not recommended


Why Multiple VIO Servers?

Second VIO Server adds extra protection to client LPARS

Allows two teams to learn VIO setup on single system

Having Multiple VIO Servers will:
– Provide you Multiple paths to your OS/Data Virtual disks
– Provide you Multiple paths to your network

Advantages:
– Highest superior availability to other virtual I/O solutions
– Allows VIO Server updates without shutting down client LPAR’s

Virtualization VIO basics

Virtualization VIO basics

The Virtual I/O Server is part of the IBM System p Advanced Power Virtualization hardware feature. Virtual I/O Server allows sharing of physical resources between LPARs including virtual SCSI and virtual networking. This allows more efficient utilization of physical resources through sharing between LPARs and facilitates server consolidation.

The Virtual I/O Server is software that is located in a logical partition. This software facilitates the sharing of physical I/O resources between AIX® and Linux® client logical partitions within the server. The Virtual I/O Server provides virtual SCSI target and Shared Ethernet Adapter capability to client logical partitions within the system, allowing the client logical partitions to share SCSI devices and Ethernet adapters. The Virtual I/O Server software requires that the logical partition be dedicated solely for its use.
The Virtual I/O Server is available as part of the Advanced POWER™ Virtualization hardware feature.
Using the Virtual I/O Server facilitates the following functions:
-->Sharing of physical resources between logical partitions on the system
-->Creating logical partitions without requiring additional physical I/O resources
-->Creating more logical partitions than there are I/O slots or physical devices available with the ability for partitions to have dedicated I/O, virtual I/O, or both
-->Maximizing use of physical resources on the system
-->Helping to reduce the Storage Area Network (SAN) infrastructure
The Virtual I/O Server supports client logical partitions running the following operating systems:
-->AIX 5.3 or later
-->SUSE Linux Enterprise Server 9 for POWER (or later)
-->Red Hat® Enterprise Linux AS for POWER Version 3 (update 2 or later)
-->Red Hat Enterprise Linux AS for POWER Version 4 (or later)
For the most recent information about devices that are supported on the Virtual I/O Server, to download Virtual I/O Server fixes and updates, and to find additional information about the Virtual I/O Server, see the Virtual I/O Server Web site.
The Virtual I/O Server comprises the following primary components:
-->Virtual SCSI
-->Virtual Networking
-->Integrated Virtualization Manager
The following sections provide a brief overview of each of these components.


Virtual SCSI
Physical adapters with attached disks or optical devices on the Virtual I/O Server logical partition can be shared by one or more client logical partitions. The Virtual I/O Server offers a local storage subsystem that provides standard SCSI-compliant logical unit numbers (LUNs). The Virtual I/O Server can export a pool of heterogeneous physical storage as an homogeneous pool of block storage in the form of SCSI disks.
Unlike typical storage subsystems that are physically located in the SAN, the SCSI devices exported by the Virtual I/O Server are limited to the domain within the server. Although the SCSI LUNs are SCSI compliant, they might not meet the needs of all applications, particularly those that exist in a distributed environment.
The following SCSI peripheral-device types are supported:
-->Disks backed by a logical volume
-->Disks backed by a physical volume
-->Optical devices (DVD-RAM and DVD-ROM)


Virtual networking
Shared Ethernet Adapter allows logical partitions on the virtual local area network (VLAN) to share access to a physical Ethernet adapter and to communicate with systems and partitions outside the server. This function enables logical partitions on the internal VLAN to share the VLAN with stand-alone servers.


Integrated Virtualization Manager
The Integrated Virtualization Manager provides a browser-based interface and a command-line interface that you can use to manage IBM® System p5™ and IBM eServer™ pSeries® servers that use the IBM Virtual I/O Server. On the managed system, you can create logical partitions, manage the virtual storage and virtual Ethernet, and view service information related to the server. The Integrated Virtualization Manager is packaged with the Virtual I/O Server, but it is activated and usable only on certain platforms and where no Hardware Management Console (HMC) is present.

Introduction to VIO

Introduction to VIO

Prior to the introduction of POWER5 systems, it was only possible to create as many separate logical partitions (LPARs) on an IBM system as there were physical processors. Given that the largest IBM eServer pSeries POWER4 server, the p690, had 32 processors, 32 partitions were the most anyone could create. A customer could order a system with enough physical disks and network adapter cards to so that each LPAR would have enough disks to contain operating systems and enough network cards to allow users to communicate with each partition.
The Advanced POWER Virtualization™ feature of POWER5 platforms1 makes it possible to allocate fractions of a physical CPU to a POWER5 LPAR. Using virtual CPU's and virtual I/O a user can create many more LPARs on a p5 system than there are CPU's or I/O slots. The Advanced POWER Virtualization feature accounts for this by allowing users to create shared network adapters and virtual SCSI disks. Customers can use these virtual resources to provide disk space and network adapters for each LPAR they create on their POWER5 system
(see Figure ).

There are three components of the Advanced POWER Virtualization feature: Micro-Partitioning™, shared Ethernet adapters, and virtual SCSI. In addition, AIX 5L Version
5.3 allows users to define virtual Ethernet adapters permitting inter-LPAR communication. This paper provides an overview of how each of these components works and then shows the details of how to set up a simple three-partition system where one partition is a Virtual I/O Server and the other two partitions use virtual Ethernet and virtual SCSI to differing degrees. What follows is a practical guide to help a new POWER5 customer set up simple systems where high availability is not a concern, but becoming familiar with this new technology in a development environment is the primary goal.

Micro-Partitioning
An element of the IBM POWER Virtualization feature called Micro-Partitioning can divide a single processor into many different processors. In POWER4 systems, each physical processor is dedicated to an LPAR. This concept of dedicated processors is still present in POWER5 systems, but so is the concept of shared processors. A POWER5 system administrator can use the Hardware Management Console (HMC) to place processors in
a shared processor pool. Using the HMC, the administrator can assign fractions of a CPU to individual partitions. If one LPAR is defined to use processors in the shared processor pool, when those CPUs are idle, the POWER Hypervisor™ makes them available to other partitions. This ensures that these processing resources are not wasted. Also, the ability to assign fractions of a CPU to a partition means it is possible to partition POWER5 servers into many different partitions. Allocation of physical processor and memory resources on POWER5 systems is managed by a system firmware component called the POWER Hypervisor.

Virtual Networking
Virtual networking on POWER5 hardware consists of two main capabilities. One capability is provided by a software IEEE 802.1q (VLAN) switch that is implemented in the Hypervisor on POWER5 hardware. Users can use the HMC to add Virtual Ethernet adapters to their partition definitions. Once these are added and the partitions booted, the new adapters can be configured just like real physical adapters, and the partitions can communicate with each other without having to connect cables between the LPARs. Users can separate traffic from different VLANs by assigning different VLAN IDs to each virtual Ethernet adapter. Each AIX 5.3 partition can support up to 256 Virtual Ethernet adapters

In addition, a part of the Advanced POWER virtualization virtual networking feature allows users to share physical adapters between logical partitions. These shared adapters, called Shared Ethernet Adapters (SEAs), are managed by a Virtual I/O Server partition which maps physical adapters under its control to virtual adapters. It is possible to map many physical Ethernet adapters to a single virtual Ethernet adapter thereby eliminating a single physical adapter as a point of failure in the architecture.
There are a few things users of virtual networking need to consider before implementing it. First, virtual networking ultimately uses more CPU cycles on the POWER5 machine than when physical adapters are assigned to a partition. Users should consider assigning a physical adapter directly to a partition when heavy network traffic is predicted over a certain adapter. Secondly, users may want to take advantage of larger MTU sizes that virtual Ethernet allows if they know that their applications will benefit from the reduced fragmentation and better performance that larger MTU sizes offer. The MTU size limit for SEA is smaller than Virtual Ethernet adapters, so users will have to carefully choose an MTU size so that packets are sent to external networks with minimum fragmentation.

Virtual SCSI
The Advanced POWER Virtualization feature called virtual SCSI allows access to physical disk devices which are assigned to the Virtual I/O Server (VIOS). The system administrator uses VIOS logical volume manager commands to assign disks to volume groups. The administrator creates logical volumes in the Virtual I/O Server volume groups. Either these logical volumes or the physical disks themselves may ultimately appear as physical disks (hdisks) to the Virtual I/O Server’s client partitions once they are associated with virtual SCSI host adapters. While the Virtual I/O Server software is
packaged as an additional software bundle that a user purchases separately from the AIX 53 distribution, the virtual I/O client software is a part of the AIX 5.3 base installation media so an administrator does not need to install any additional filesets on a Virtual SCSI client partition. Srikrishnan provides more details on how the Virtual SCSI feature works

Vmstat o/p

vmstat - Report virtual memory statistics Summary of overall system usage vmstat reports information about processes, memory, paging, block IO, traps, and cpu activity.
The first report produced gives averages since the last reboot. Addi- tional reports give information on a sampling period of length delay. The process and memory reports are instantaneous in either case.
Example : To see usage averaged over 5-second intervals - but display only 8 lines
# vmstat 5 8
procs memory swap io system cpu r b w swpd free buff cache si so bi bo in cs us sy id 0 0 0 0 207904 5760 20524 0 0 86 30 117 47 1 2 96 0 0 0 0 207904 5776 20524 0 0 0 5 103 12 0 0 100 0 0 0 0 207904 5780 20524 0 0 0 1 108 26 0 0 100 0 0 0 0 207904 5780 20524 0 0 0 1 106 19 0 0 100 0 0 0 0 207904 5792 20524 0 0 0 5 112 33 0 0 100 0 0 0 0 207904 5796 20524 0 0 0 7 108 19 0 0 100 0 0 0 0 207904 5808 20524 0 0 0 4 108 24 0 0 100 0 0 0 0 207904 5808 20524 0 0 0 1 107 22 0 0 100
The Table show 6 categories of information on the first line and furtherdetails of each of the major fields
FIELD DESCRIPTIONS Procs - The number of processes and their types
r: The number of processes waiting for run time. b: The number of processes in uninterruptable sleep,which means they are waiting on a resource w: The number of processes swapped out but otherwise ready to run
Memory - Info about physical memory and swap space
swpd: the amount of virtual memory used (kB). free: the amount of idle [free] physical memory (kB). buff: the amount of memory used as buffers (kB). cache: virtual memory that's cached
Swap - Amount of swapping si: Amount of memory swapped in from disk (kB/s). so: Amount of memory swapped to disk (kB/s).
Note : Higher numbers here indicate too much swapping IO - Info about input and output
bi: Blocks sent to a block device (blocks/s). bo: Blocks received from a block device (blocks/s).
Note : Higher numbers here indicate too much disk activity
System - Information about the system
in: The number of interrupts per second, including the clock. cs: The number of context switches per second. i.e. the number of times the kernel changes which process is running
CPU These are percentages of total CPU time used us: % of time used by User process - user time sy: % of time used by system processes - system time id: % of time the CPU was idle - idle time
All linux blocks are currently 1k, except for CD-ROM blocks which are 2k.
See : /proc/meminfo /proc/stat

Important Notes while working on AIX

Important Notes while working in AIX


Note1- To Check Serial port connectivity (for HACMP), connect serial cable between two systems:-

On one server run
# cat < /dev/tty1

On second server run
# ls > /dev/tty1

Note2- Below is the steps / tips to keep in mind while calculating space in KB (512 or 1024):-

While calculating bytes for increase and decrease file system size, first check it is in 512KB blocks or 1024KB blocks.

Calculations-
Increase file system size in MB-
Formula- “MB to increase * 1024 = Value Multiply by 2 + Current bytes” = Total file system size in MB.
(Note- You have to multiply by two only when the existing file system is in 512KB Blocks and not requires to multiply when it is already in 1024KB Blocks)

Increase file system size in GB-
Formula- “GB to increase * 1024 * 1024 = Value Multiply by 2 + Current bytes” = Total file system size in GB.
(Note- You have to multiply by two only when the existing file system is in 512KB Blocks and not requires to multiply when it is already in 1024KB Blocks)

Note3- While restoring the mksysb in other machine, we can change the attributes in bosinst.data file, that is backed up with mksysb. Like- #vi bosinst.data

Note4- To identify the type of system hardware capability you have, either 32-bit or 64-bit, execute the bootinfo -y command. If the command returns a 32, you cannot use the 64-bit kernel.

Note5- The AIX 5L operating system previously contained both a uniprocessor and a multiprocessor 32-bit kernel. Effective with AIX 5L Version 5.3, the operating system supports only the multiprocessor kernel, regardless of the number of physical processors.

Note6- Types of VG’s and limitations.

Note7- To set any command to run by default during system boot, add the command in /etc/rc file.
For example- We can add the commands in rc file /usr/bin/quotacheck –a and /usr/bin/quotaon –a.

Note8- The default signal sending by kill command is terminate signal - “SIGTERM”, Signal no. 15. The signal names are listed in /usr/include/sys/signal.h.

Note9- Most common SIGNALS used by kill command are-
15- SIGTERM (Terminate) (Default)
9- SIGKILL (KILL)
18- SIGTSTP (STOP)

Note10- Svmon command display the current state of virtual memory in nine different parts-
1. global
2. user
3. command
4. class
5. tier
6. process
7. segment
8. detailed segment
9. frame

The flags and detailed information can be found at web site- http://publib.boulder.ibm.com/infocenter/pseries/index.jsp.

Note11- Startsrc, stopsrc and refresh command sends request to SRC to start, stop or refresh the sub-system, group of subsystems or subserver.

Note12- Zombie processes display as when listed by the ps command.

Note13- By using CTRL-C function in running command, you can cancel the whole process.

Note14- By using CTRL-Z function in running command, it will stop the process immediately.

Note15- The wildcard characters are- asterisk (*) and question mark (?).
Where, The metacharacters are- open and close square brackets ([ ]), hyphen (-), and exclamation mark (!).

Note16- When using smit menu for configuration, the wildcards meaning are-
* - Means mandatory things you have to select while using SMIT.
# - Numeric parameter.
+ - List of options available, can check with drop down menu.
/ - Full path is required.

Note17- In AIX5L AIX print subsystem is already configured. To enable System V Printing subsystem in AIXL, you have to installed the packages from AIX base CD.

Note18- Smitty installp command stores information if maintenance, removal and installation of packages in /var/adm/sw/installp.log, and some detailed information in $HOME/smit.log and $HOME/smit.script.

Note19- By default, when the instfix command is run from the command line, the command uses stdout and stderr for reporting. If you want to generate an installation report, you will need to redirect the output.
For example:
#instfix -aik IY73748 > /tmp/instfix.out 2> /tmp/instfix.err

Note20- Types of AIX Installations and difference between them-
New and complete overwrite
Preservation and
Migration

The difference is-

Note21- Default IP’s for HMC Ports on server are-
HMC Port1- 192.168.2.147
HMC Port2- 192.168.3.147
These IP’s are default for new p-series server until change.

Note22- Authentication for server HMC port is-
User – admin
Password- password
This is default until changed.

Note23- Default IP for HMC’s Ethernet port is-
eth0- 192.168.3.143

Note24- User name and password for HMC system login is-
User- hmcroot
Pass- abc123
This is default comes with system until changed.

Note25- Default IP for IBM SAN Switch management port is-
Management port- 10.77.77.77
This is default comes with all switches until changed.

Note26- Default IP’s for SAN Storage (DS4300) management ports are-
Controller A management port- 192.168.128.101
Controller B management port- 192.168.128.102
Subnet mask- 255.255.255.0
This is default comes with storage DS4300 until changes.

Note27- System booting modes are-
Normal mode
System management services (SMS)
Maintenance mode
Diagnostics

Note28- 32767 Users can connect with AIX server at single time.

Note29- First 512 bytes in hdd reserved for VGDA and Quoram.

Note30- CAPP EL4 is for SSL in AIX and TCB – Trusted computing base, it is for security reasons, we can restore some important files with tcbck commands.

Note31- Crontab command uses the following format-

minutes hours day-of-month monthly weekday “command”
0 to 59 0 to 23 1 to 31 1 to 12 0 to 6
(0 for Sunday)

For every we can use wildcard- *.

Note32- File /etc/environment is to set the basic environments for the system.

Note33- System is using following file sequence when user logged in the system:-


/etc/motd (Global, for all users)
/etc/profile (Global environments for all users)



$HOME/.profile (Single user wise environment settings)



$HOME/.hashlogin (If this file is created, message from motd will be hidden)


Note33- To clear the wall and console messages, use “esc+ctrl+l” key.

Note34- In HACMP, minimum nodes capacity is 2 and maximum is 32.

Note35- Four different types of hardware platform (Architectures) are-

RS6k: RS6000 (MCA-based uni-processor models)
RS6kSMP: RS6000 SMP (MCA-based symmetric multiprocessor models)
RSPC: ISA-bus models
CHRP: Common hardware reference platform (PCI-bus models)

Note36- Format for the date command is:-

mmddHHMMccyy, where mm-Month, dd-day, HH-Hour, MM-Minutes, and ccyy is for century and year.

Note37- Logical track group (LTG) size is the maximum allowed transfer size for an I/O
disk operation.

Note38- While working with errpt commands, these things are required to keep in mind-

Classes: General source of the error, the possible error classes are:

H Hardware.
S Software.
O Informational messages.
U Undetermined.

Type: Severity of the error that has occurred. The following types of errors are possible-
PEND The loss of availability of a device or component is imminent.

PERF The performance of the device or component has degraded to below an acceptable level.

PERM A condition that could not be recovered from. Error types with this value are usually the most severe errors and are more likely to mean that you have a defective hardware device or software module. Error types other than PERM usually do not indicate a defect, but they are recorded so that they can be analyzed by the diagnostics
programs.

TEMP A condition that was recovered from after a number of unsuccessful attempts. This error type is also used to record informational entries, such as data transfer statistics for DASD devices.

UNKN It is not possible to determine the severity of the error.

INFO The error log entry is informational and was not the result of an error.

Note39- While taking backup of rootvg or uservg, it will take only filesystem that is mounted, unmounted file systems and raw devices will not include in vg backup.

Note40- Spilliting a VG means to divide the mirrored VG in to two VG’s. We can give the new VG name in splitvg command. The pv for splitvg will show as snapshot pv. To rejoin the vg, can use the command – joinvg VGNAME.

Note41- Types of devices in UNIX are-

Block device: Block device is a structured random access device. Buffering is used to provide a block-at-a-time method of access. Usually only disk file systems.

Character (raw) device: Character (raw) device is a sequential, stream-oriented device which provides no buffering.

Tips- Most block devices also have an equivalent character device. For example, /dev/hd1 provides buffered access to a logical volume whereas /dev/rhd1 provides raw access to the same logical volume.

Tips- To identify the block and character device, we can see the difference between them with #ls –l /dev command, in the beginning of device file, it will show b letter for block device and c for character device.

Some of the commonly used block and character devices in system are-

Examples of block devices:
cd0 CD-ROM
fd0, fd0l, fd0h Diskette
hd1, lv00 Logical Volume
hdisk0 Physical Volume

Examples of character (raw) devices:
console, lft, tty0 Terminal
lp0 Printer
rmt0 Tape Drive
tok0, ent0 Adapter
kmem, mem, null Memory
rfd0, rfd0l, rfd0h Diskette
rhd1, rlv00 Logical Volume
rhdisk0 Physical Volume

Major and minor numbers: Major number refers to the software section of code in the kernel which handles that type of device, and the minor number to the particular device of that type.

Note42-
SRC: The System resource controller provides a set of commands to make it easier for the administrator to control subsystems.

Subsystem, Subserver and group of Subsystems: A subsystem is a program (or a set of related programs) designed to perform a function. This can be further divided into subservers. Some subsystem have subservers. Subservers are similar to daemons. SRC was designed to minimize the need for user intervention since it provides control of individual subsystem or groups of subsystems with a few commands.

Example: The tcp/ip group contains a subsystem, inetd, that has several subservers, for example ftp and telnet.

Note43-
VGDA: The Volume Group Descriptor Area (VGDA) is an area of disk, at least one per
PV, containing information for the entire VG. It contains administrative information about the volume group (for example, a list of all logical volume entries, a list of all the physical volume entries and so forth). There is usually one VGDA per physical volume. The exceptions are when there is a volume group of only either one or two.
In exception case, If VG contain only one hdd, there will be two VGDAs and if VG contain two hdd, then total VGDA’s will be 3, two VGDAs one disk and one VGDA on second disk.

Quorum: There must be a quorum (quorum meaning in dictionary is - minimum number of members that must be present to constitute a valid meeting) of VGDAs available to activate the volume group and make it available for use (varyonvg). A quorum of VGDA copies is needed to ensure the data integrity of management data that describes the logical and physical volumes in the volume group. A quorum is equal to 51% or more of the VGDAs available.

Tips: A system administrator can force a volume group to varyon without a quorum. This is not recommended and should only be done in an emergency.

Note44- For starting subsystems and subservers automatically while machine booting, edit file /etc/rc.tcpip and remove the hash mark from particular stanza.

Note45- Password to go in SMS menu -
Password- admin
This is default until changed.

Note46- Two types of modes available to set securities on files and directories. There are-


1. Symbolic mode
2. Numeric or absolute mode


1. Symbolic mode:
To specify a mode in symbolic form, you must specify three sets of flags.

The first set of flags specifies who is granted or denied the specified permissions,
as follows:
u File owner.
g Group and extended ACL entries pertaining to the file's group.
o All others.
a User, group, and all others. The a flag has the same effect as specifying the ugo flags together. If none of these flags are specified, the default is the a flag and the file creation mask.

(umask) is applied.

Tip: Do not separate flags with spaces.

The second set of flags specifies whether the permissions are to be removed, applied, or set:
- Removes specified permissions.
+ Applies specified permissions.
= Clears the selected permission field and sets it to the permission specified. If you do not specify a permission following =, the chmod command removes all permissions from the selected field.

The third set of flags specifies the permissions that are to be removed, applied, or set:
r Read permission.
w Write permission.
x Execute permission for files; search permission for directories.
X Execute permission for files if the current (unmodified) mode bits have at least one of the user, group, or other execute bits set. The X flag is ignored if the File parameter is specified and none of the execute bits are set in the current mode bits.

These flags set the search permissions for directories:
S Set-user-ID-on-execution permission if the u flag is specified or implied. Set-group-ID-on-execution permission if the g flag is specified or implied.
t For directories, indicates that only file owners can link or unlink files in the specified directory. For files, sets the save-text attribute.


2. Numeric or absolute mode:
The chmod command also permits you to use octal notation for the mode. The
numeric mode is the sum of one or more of the following values:

4000 Sets user ID on execution.
2000 Sets group ID on execution.
1000 Sets the link permission to directories or sets the save-text attribute for files.
0400 Permits read by owner.
0200 Permits write by owner.
0100 Permits execute or search by owner.
0040 Permits read by group.
0020 Permits write by group.
0010 Permits execute or search by group.
0004 Permits read by others.
0002 Permits write by others.
0001 Permits execute or search by others.

Note47- During system boot, fsck command will by default scan and fix if any errors found for four file systems, these are-

/
/usr
/var
/tmp.

Note48- By default devices / logical volumes are created in rootvg while installing new system with AIX-

LV NAME TYPE LPs PPs PVs LV STATE MOUNT POINT
hd5 boot 1 2 2 closed/syncd N/A
hd6 paging 4 8 2 open/syncd N/A
hd8 jfs2log 1 2 2 open/syncd N/A
hd4 jfs2 1 2 2 open/syncd /
hd2 jfs2 9 18 2 open/syncd /usr
hd9var jfs2 1 2 2 open/syncd /var
hd3 jfs2 1 2 2 open/syncd /tmp
hd1 jfs2 1 2 2 open/syncd /home
hd10opt jfs2 1 2 2 open/syncd /opt

Note49- To go in SMS menu while system startup, press “1” and to select factory default bootlist press “5”.

How to add a new machine into Nim

Prequiest are
The disk should not be mirrored.
You should must be knowing the IP address of the enthernet port of the server which u will be giving to the server.
We need to make one Master and others as there Clients .
Required to set the ip address of the master server and the ulimits . Step that needs to be followed at the Master end are as follows :
Step 1) Insert cd1 of the os base cd and run nim_master_setup command .
It will take time and automaically configure the required setup , it will rake nearly 5-10 mins to complete .
Step 2) Type vi /etc/host ......in this add the entire of your client machines .
ie . you need u need to give ip address and the host name .
Step 3) Once this is done then run smitty nim command
A: Select Perform Nim Administration Task .
(1) Manage Machine . * define Machine ..........in this u will need to give the hostname of ur client machine . (then press esc+3)
(2) Manage Network Install Resource Allocation .
* Allocate Network Install Resources ..........in this it will show u host name of master and clients , need to select client . .............once u have selected client machine it will show u the list of the thigs that will be install , need to select all the things (3) Perform Operations on Machine . * Select
This complete all the settings that needs to be do on the Master Server .
Step that needs to be followed at the Client end are as follows :
Step 1) Boot the client server in SMS menu select the 2 option ie Remote IPL
Step 2) Give ip address , subnet mask , host name of the client machine.
Step 3) Make sure that protocal used is normal instead of IEEE802.1 .
Step 4) The spanning tree should be not seleceted ie it should be off .
Step 5) It will give u option to test ur ping select that and check it the output will be ping sucessfull .
Step 6) Press X and logout of the SMS menu the installation will start and it will take nearly 15-20 for the installation to be complete .
This complete all the settings that needs to be do on the Client Server .
And this complete NIM installation .

How to remove a tape Drive from a lpar

To remove Tape Drive :

Step 1 )
Go to Lpar to whom its assigned
a) rmdev –dl rmt0
b) lsdev –Cl cd0 –F Parent
ide0
c) lsslot –c slot –l ide0
slot no T12 pci2 ide0
d) rmdev –l pci2 –R ( R – to remove child process too)
cd0 defined
ide0 defined
pci2 defined
or
e) rmdev –l pci2
f) rmdev –l ide0

Go to Lpar right clik on particular lpar à Dynamic logical partitionà Physical adaptor resource à remove Select the slot T12 and clik OK

A script which is used to recove a rootvg when rootvg failed

# cat rvgrecover
VG=rootvg
PV=hdisk0
cp /etc/objrepos/CuAt /etc/objrepos/CuAt.orig cp /etc/objrepos/CuDep /etc/objrepos/CuDep.orig cp /etc/objrepos/CuDv /etc/objrepos/CuDv.orig cp /etc/objrepos/CuDvDr /etc/objrepos/CuDvDr.orig
lqueryvg -Lp hdisk0 awk '{print $2}'while read LVname;
do
odmdelete -q "name=$LVname" -o CuAt
odmdelete -q "name=$LVname" -o CuDv
odmdelete -q "name=$LVname" -o CuDvDr
done
odmdelete -q "name=$VG" -o CuAt
odmdelete -q "parent=$VG" -o CuDv
odmdelete -q "name=$VG" CuDep
odmdelete -q "dependency=$VG" -o CuDep
odmdelete -q "value1=10" -o CuDvDr
odmdelete -q "value3=$VG" -o CuDvDr
importvg -y $VG $PV #Ignore lvaryoffvg errors
varyonvg $VG

Nfs configuration and Auto mount

Server Side.
We want to mount the /backup NFS directory from 10.0.128.114 to 10.0.252.88 server
# mknfsexp -d /backup -t ro -h 10.0.252.88-----------------------------------------------------------------------------------------------------------------
Client Side
# mknfsmnt -f /backup1 -d /backup -h 10.0.128.114
The above command mount the /backup to /backup1 on 10.0.252.88 server




############### Using AutoFS to automatically mount a file system #############

AutoFS relies on the use of the automount command to propagate the automatic mount configuration information to the AutoFS kernel extension and start the automountd daemon. Through this configuration propagation, the extension automatically and transparently mounts file systems whenever a file or a directory within that file system is opened. The extension informs the automountd daemon of mount and unmount requests, and the automountd daemon actually performs the requested service.
Because the name-to-location binding is dynamic within the automountd daemon, updates to a Network Information Service (NIS) map used by the automountd daemon are transparent to the user. Also, there is no need to premount shared file systems for applications that have hard-coded references to files and directories, nor is there a need to maintain records of which hosts must be mounted for particular applications.

AutoFS allows file systems to be mounted as needed. With this method of mounting directories, all file systems do not need to be mounted all of the time; only those being used are mounted.

For example, to mount an NFS directory automatically:
Verify that the NFS server has exported the directory by entering:

# showmount -e ServerName

where ServerName is the name of the NFS server. This command displays the names of the Directories currently exported from the NFS server.
Create an AutoFS master file and map file. AutoFS mounts and unmounts the directories specified in these map files.

For example, suppose you want AutoFS to mount the /local/dir1 and /local/dir2 directories as needed from the serve1 server onto the /remote/dir1 and /remote/dir2 directories, respectively. The auto_master file entry would be as follows:


/remote /tmp/mount.map
The /tmp/mount.map file entry would be as follows:

dir1 -rw serve1:/local/dir1dir2 -rw serve1:/local/dir2


Ensure that the AutoFS kernel extension is loaded and the automountd daemon is running.
This can be accomplished in two ways: Using the automount command: Issue

/usr/bin/automount -v.
Using SRC: Issue lssrc -s automountd. If the automountd subsystem is not running, issue

startsrc -s automountd.


Note: Starting the automountd daemon with the startsrc command will ignore any changes that have been made to the auto_master file.
To stop the automount daemon, issue the stopsrc -s automountd command. If, for some reason, the automountd daemon was started without the use of SRC, issue:

kill automountd_PID

where automountd_PID is the process ID of the automountd daemon. (Running the ps -e command displays the process ID of the automountd daemon.) The kill command sends a SIGTERM signal to the automountd daemon

How to set up a quota in AIX

######### Procedure to set up the disk quota ############################
To set up the disk quota system, use the following procedure:
1. Log in with root authority.
2. Determine which file systems require quotas.
3. Use the chfs command to include the userquota and groupquota quota configuration attributes in the /etc/filesystems file.
The following example uses the chfs command to enable user quotas on the /home file system:
# chfs -a "quota = userquota" /home
To enable both user and group quotas on the /home file system, type:
# chfs -a "quota = userquota,groupquota" /home
The corresponding entry in the /etc/filesystems file is displayed as follows:
/home: dev = /dev/hd1 vfs = jfs log = /dev/hd8 mount = true check = true quota = userquota,groupquota options = rw
4. The following example uses the chfs command to establish user and group quotas for the /home file system and names the myquota.user and myquota.group quota files:
# chfs -a "userquota = /home/myquota.user" -a "groupquota = /home/myquota.group" /home
# The following example entry shows quota limits for the gpsilva user:
Quotas for user gpsilva:
/home: blocks in use: 30, limits (soft = 100, hard = 150) inodes in use: 73, limits (soft = 200, hard = 250)
This user has used 30 KB of the maximum 100 KB of disk space. Of the maximum 200 files, gpsilva has created 73. This user has buffers of 50 KB of disk space and 50 files that can be allocated to temporary storage.
5. To duplicate the quotas established for user gpsilva for user tneiva, type:
# edquota -p gpsilva tneiva
6. Enable the quota system with the quotaon command. The quotaon command enables quotas for a specified file system or for all file systems with quotas (as indicated in the /etc/filesystems file) when used with the -a flag.
7. Use the quotacheck command to check the consistency of the quota files against actual disk usage.
# very IMP
To enable this check and to turn on quotas during system startup, add the following lines at the end of the /etc/rc file:
echo " Enabling filesystem quotas "
/usr/sbin/quotacheck -a /usr/sbin/quotaon -a


########## Some examples #################
There are related commands, namely the edquota command, quotacheckcommand, and repquota command.
The following examples show the commands in typical uses:
1. To enable user quotas for the /usr/Tivoli/tsm/server/db file system,
# quotaon -u /usr/Tivoli/tsm/server/db
2. To disable user and group quotas for all file systems in the /etc/filesystems and print a message, enter:
# quotaoff -v -a
3. To display your quotas as user neivac, type:
$ quota
The system displays the following information:
User quotas for user neivac (uid 502):
Filesystem blocks quota limit grace Files quota limit grace
/u 20 55 60 20 60 65
4. To display quotas as the root user for user gpsilva, type:
quota -u gpsilva
The system displays the following information:
User quotas for user gpsilva (uid 2702):
Filesystem blocks quota limit grace files quota limit grace
/u 48 50 60 7 60 60


# To disable the quota use the command
# quotaoff -a ===> it disables the quota for all file systems.
# quotaoff -u username ===> it disables the quota for the users.
# Quotaoff -g groupname ===> it disables the quota for the groups.

File Systems IN AIX

# File Systems Types:
JFS, EJFS, NFS, CD-ROM File systems
# File Systems Structure:
1. Superblock ==> it contains control information about file systems such as a) Size of the file systems b) Name of the file systems c) The System log device d) The version number e) The number of inodes f) List of free inodes and data-bocks g) Date and time of creation of file system and also file system state.
IMP: Corruption of data may render the file system unusable. This is wny system keeps a second copy of superblock on logical block 31.

2. Allocation Group ==> it consists of inodes and it corresponding data blocks. An allocation group spans multiple adjacent disk blocks and it improves the speed of i/o operation. Booth jfs and jfs2 file systems use allocation group.

3. Inodes ===> it contains control information about file such as a) Type, Size, Owner, and the date and time when the file was created, modified, last accessed. b) it also contains the pointers to data blocks that store the actula data of file. Every File has a corresponding inode. c) The jfs restricts all file systems to 16 MB inodes.
4. Data Blocks ==> it stores the actucal data of the file or pointers to other data blocks. Default value for disk block size is 4 kb.
5. Fragments ===> Fragments of logical blocks can be used to support files smaller than the standard size of the logical boock ( 4 kb ). This rules applies only to last block of a file smaller than 32 kb.




############### File Systems Differences ########################################

Function JFS JFS2
Architectural maximum file system size 1 TB 4 PB
Architectural maximum file size 64 GB 4 PB
No of inodes Fixed, set at Dynamic system creation
Inode size 128 bytes 512 bytes
Fragment size 512 512
Block size 4096 4096
Directory organization Linear B-tree
Compression Yes No
Default ownership at creation sys.sys root.system
SGID of default file mode SGID=on SGID=off
Quotas Yes Yes



####################### Example of file system creation #####################################################
Creating file systems without specifying logical volumes
# lsvg -l testvg
testvg:LV NAME TYPE LPs PPs PVs LV STATE MOUNT POINT
# crfs -v jfs -g testvg -a size=10M -m /fs1
Based on the parameters chosen, the new /fs1 JFS file systemis limited to a maximum size of 134217728 (512 byte blocks)New File System size is 262144
# crfs -v jfs2 -g testvg -a size=10M -p ro -m /fs2
File system created successfully.130864 kilobytes total disk space.New File System size is 262144

# lsvg -l testvg
testvg:LV NAME TYPE LPs PPs PVs LV STATE MOUNT POINTloglv00 jfslog 1 1 1 closed/syncd N/Alv00 jfs 1 1 1 closed/syncd /fs1loglv01 jfs2log 1 1 1 closed/syncd N/Afslv00 jfs2 1 1 1 closed/syncd /fs2
# lslv lv00
LOGICAL VOLUME: lv00 VOLUME GROUP: testvgLV IDENTIFIER: 00c478de00004c0000000107d96de510.2 PERMISSION:read/writeVG STATE: active/complete LV STATE: closed/syncdTYPE: jfs WRITE VERIFY: offMAX LPs: 512 PP SIZE: 128 megabyte(s)COPIES: 1 SCHED POLICY: parallelLPs: 1 PPs: 1STALE PPs: 0 BB POLICY: relocatableINTER-POLICY: minimum RELOCATABLE: yesINTRA-POLICY: middle UPPER BOUND: 32MOUNT POINT: /fs1 LABEL: /fs1MIRROR WRITE CONSISTENCY: on/ACTIVEEACH LP COPY ON A SEPARATE PV ?: yesSerialize IO ?: NO
# lslv fslv00
LOGICAL VOLUME: fslv00 VOLUME GROUP: testvgLV IDENTIFIER: 00c478de00004c0000000107d96de510.4 PERMISSION:read/writeVG STATE: active/complete LV STATE: closed/syncdTYPE: jfs2 WRITE VERIFY: offMAX LPs: 512 PP SIZE: 128 megabyte(s)COPIES: 1 SCHED POLICY: parallelLPs: 1 PPs: 1STALE PPs: 0 BB POLICY: relocatableINTER-POLICY: minimum RELOCATABLE: yesINTRA-POLICY: middle UPPER BOUND: 32MOUNT POINT: /fs2 LABEL: /fs2MIRROR WRITE CONSISTENCY: on/ACTIVEEACH LP COPY ON A SEPARATE PV ?: yesSerialize IO ?: NO
# cat /etc/filesystemsgrep -ip fs1
/fs1:dev = /dev/lv00 vfs = jfslog = /dev/loglv00mount = falseaccount = false




# Mount -a ===> mount all the file systems


# mount ===> Disply mounted file systems
# mount node mounted mounted over vfs date options-------- --------------- --------------- ------ ------------ ---------------/dev/hd4 / jfs2 Nov 27 12:36 rw,log=/dev/hd8/dev/hd2 /usr jfs2 Nov 27 12:36 rw,log=/dev/hd8/dev/hd9var /var jfs2 Nov 27 12:36 rw,log=/dev/hd8/dev/hd3 /tmp jfs2 Nov 27 12:36 rw,log=/dev/hd8/dev/hd1 /home jfs2 Nov 27 12:36 rw,log=/dev/hd8/proc /proc procfs Nov 27 12:36 rw/dev/hd10opt /opt jfs2 Nov 27 12:36 rw,log=/dev/hd8/dev/testlv /test jfs2 Nov 28 19:54



# lsfs ===> Shows the characteristics of a file systems
# rmfs ===> removes the file systems
# lsvg -l testvg
testvg:LV NAME TYPE LPs PPs PVs LV STATE MOUNT POINTloglv00 jfslog 1 1 1 closed/syncd N/Alv00 jfs 1 1 1 closed/syncd /fs1loglv01 jfs2log 1 1 1 open/syncd N/Afslv00 jfs2 1 1 1 closed/syncd /fs2testlv jfs2 1 1 1 open/syncd /test

########################### Removing the file Systems ###############################################################
# rmfs /test
rmfs: 0506-921 /test is currently mounted.
# umount /test
# rmfs /test
rmlv: Logical volume testlv is removed.
# lsvg -l testvg
testvg:LV NAME TYPE LPs PPs PVs LV STATE MOUNT POINTloglv00 jfslog 1 1 1 closed/syncd N/Alv00 jfs 1 1 1 closed/syncd /fs1loglv01 jfs2log 1 1 1 closed/syncd N/Afslv00 jfs2 1 1 1 closed/syncd /fs2
# cat /etc/filesystemsgrep test#

###### Changing the attributes of file systems ####################################
# chfs -a size=250M -p rw /fs2
Filesystem size changed to 524288

# fsck ===> Checks the Systems consistency and interactively repairs the file systems. Always run the fsck command on the mounted file systems.

################ if 1st superblock corrupted then how to recover #############################################
If you receive one of the following errors from the fsck or mount commands, theproblem may be a corrupted superblock:
fsck: Not an AIX3 file systemfsck: Not an AIXV3 file systemfsck: Not an AIX4 file systemfsck: Not an AIXV4 file systemfsck: Not a recognized file system typemount: invalid argument
The problem can be resolved by restoring the backup of the superblock over theprimary superblock using one of the following commands:
# dd count=1 bs=4k skip=31 seek=1 if=/dev/lv00 of=/dev/lv00



############ Not able to umount the file systems ###############################
# Files are open within a file system. Close these files before the file system can be unmounted. The fuser command is often the best way to determine the process IDs for all processes that have open references within a specified file system. The process having an open reference can be killed by using the kill command and the unmount can be accomplished.
# If the file system is still busy and not getting unmounted, this could be due to a kernel extension that is loaded, but exists within the source file system. The fuser command will not show these kinds of references, because a user process is not involved. However, the genkex command will report on all loaded kernel extensions.

# find /home -type d -exec fuser -u {} \;/home:/home/lost+found:/home/guest:/home/kenzie: 3548c(kenzie)

ssh without password

This Procedure for do the ssh for without asking password only for One server
a@A:~> ssh-keygen -t rsa
Now use ssh to create a directory ~/.ssh as user b on B. (The directory may already exist, which is fine):a@A:~> ssh b@localhost mkdir -p .sshb@localhost's password:
Finally append a's new public key to b@B:.ssh/authorized_keys and enter b's password one last time:a@A:~> cat .ssh/id_rsa.pub ssh b@B 'cat >> .ssh/authorized_keys'b@B's password:
From now on you can log into B as b from A as a without password:a@A:~> ssh b@B hostnameB
=====================================================================================

Login in ServerA
Go to Home dircetory of user.
scp /home/oracle/.ssh/id_rsa.pub ServerB:/home/oracle/.ssh/authorized_keys
Then you will able to login without asking password to SerevrB.
You can login ServerB
run the command
ssh-keygen -t rsa
scp /home/oracle/.ssh/id_rsa.pub ServerA:/home/oracle/.ssh/authorized_keys
Then you will able to login without asking password to SerevrA

Changing the login screen welcome message

To prevent displaying certain information on login screens, edit the herald parameter in the
/etc/security/login.cfg file. The default herald contains the welcome message that displays with your login prompt. To change this parameter, you can either use the chsec command or edit the file directly.
The following example uses the chsec command to change the default herald parameter:
# chsec -f /etc/security/login.cfg -a default -herald "Unauthorized use of this system is Prohibited.\n\nlogin: "

To edit the file directly, open the /etc/security/login.cfg file and update the herald parameter as follows:
default:
herald ="Unauthorized use of this system is prohibited\n\nlogin:"
sak_enable = false
logintimes =
logindisable = 0
logininterval = 0
loginreenable = 0
logindelay = 0