Split and Joining a Volume Group in AIX

Splitting refers to the process of a breaking a mirrored Volume Group, which can be imported and used in a different AIX Machine or a LPAR. Applicaton Portability with less downtime are executed using the Splitting and Join Operation.

Scenario:

Consider an application configured on a volume group called "Application" which is made up of hdisk0 and hdisk1. And the application is mirrored.

Note: Only a mirrored volume group can be splitted.

Steps to Split:

1) # lsvg -o

2) # lsvg -l application /* Check the VG is mirrored */

3) # lsvg -p application  /* PV's used to make the Volume Group*/

4) # splitvg -y <new vgname> -c 2 application /* Splitting application VG to a new VG, if no new name is givethen the VG is created with the default name vg00 */

5) New VG name is given as say "backupappln"

6) The VG "backupappln" is created in the PV hdisk. Where hdisk1 was a part of mirrored VG application.

7) Verify the new VG Created.

8) # lsvg - l backupappln

9) # lsvg -l application

10)  # lsvg -p application

The output will still show that the VG application is made up of hdisk0 and hdisk1 but the state of hdisk1would be snapshotlv.


11) # lsvg -p backupappln

The output will show only the hdisk1

12) Now we export the VG backupappln to be used in a different machine. Before exporting the VG backupappln make sure that there is no Open Logical Volume and Varyoff the VG.
    
     # varyoffvg backupappln
 
13) # exportvg backupappln

14) # rmdev -Rdl hdisk1 /* The disk hdisk1 has been removed from the AIX Machine */

15) # lsdev -l hdisk1 /* Ensure the hdisk1 is not shown */

16) Connect the hdisk1 to the required machine.

17) # cfgmgr /* Look for the newly connected device */

18) # lsdev -l hdisk1 /* Check the status of hdisk */

19) # importvg -y VG Name PV Name

VG Name : backupappln and PV Name : hdisk1

20) # lsvg -o /* Output will show the VG backupappln */

21) # lsvg -l backappln /* List the LV's in the VG */

22) By default all the LV's  and mountpoints are prefixed with "fs".

23) # chlv -n newname oldname /* To change the name of the LV's

24) # chfs -m newmount point filesystem /* To change the mount point */

25) # mount -a /* To mount the file system *.

VIOS Operation-3

Management of Virtual/Shared Devices:

To create a virtual target device that maps lv20 as a virtual disk for a client partition hosted by the vhost0 virtual server adapter :

# mkvdev -vdev lv20 -vadapter vhost0

To create a virtual target device that maps hdisk5 as a virtual disk for a client partition hosted by the vhost1 virtual server adapter :

# mkvdev -vdev hdisk5 -vadapter vhost1

To create a SEA that maps the physical Ethernet adapter ent4 as a virtual adapter for the clien tpartitions served by the virtual Ethernet adapters ent6 and ent7, using ent6 as the default adapter and 8 as the default id :

# mkvdev -sea ent4 -vadapter ent6,ent7 -default ent6 -defaultid 8

Assign IP Address:

# mktcpip -hostname <Hostname> -interface ent# -inetaddr <IP> -netmask -gateway <IP> -start

To remove a virtual target device vtscsi9 along with its backing lv:

# rmdev -vdev vtscsi9

To remove all virtual target device associated with backing device lv001 :

# rmdev -vdev lv001

To remove a specific virtual target device :

# rmdev -vtd vtscsi0

VIOS Operation-2

Device Configurations:


1) # cfgdev /*To configures the devices in the VIO server*/


2) # cfgdev -dev  /*To configures the devices attached to scsi0 adapter*/


3) # chdev -dev <****> -attr <attribute=value> -perm /*To change the attribute of a device permanently*/


4) # chpath -dev hdisk1 -pdev scsi0 -op disable /*To disable the path between hdisk1 and scsi0*/


5) # rmdev -dev /dev/cd0 /*To unconfigure the cd-rom device*/


6) # rmdev -recursive -dev scsi /*To unconfigure scsi adapter and its child devices*/


7) # rmdev -pdev pci0  /* To unconfigures the children of pci1 but not the PCI bus pci1 */
 

VIOS Operation

Commands to Backup VIOS:

1) # backupios -cd /dev/cd0 -cdformat /*Backup VIOS on CD*/

2) # backupios -cd /dev/dvd -udf   /*Backup VIOS on DVD */

3) # backupios -tape /dev/rmt0 /*Backup VIOS on Tape*/

4) # backupios -file /tmp/filename /*Backup VIOS on a file*/

5) # backupios -tape /dev/rmt0 -verify /*Verify the Backup*/

HMC Operations

This posts covers the steps to be followed in taking backup of Manager Partition Profile data.

The Operations Performed are:

Backup * Restore * Initialize * Delete

1) Taking Backup of Managed Partition Profile

Open HMC->On the Workpane->Select System Management->Servers->Select the desired the Managed System.

2) Once the Managed System is selected->Check the Check Box->Click on the >> icon that appears on the Managed System.

3) Right click on the >> icon->Select "Manage Partition Data"->Select "Backup/Restore/Delete/Initialize".

System Dump

System Dump Device is used for Crash Recovery.

By default  /dev/hd6 is assigned for Dump.

Steps to create a dump device:

1) Estimate the amount of size required to create a dump device:

# sysdumpdev -e

The output is shown in bytes.

2) Check the free PP's available in rootvg.

# lsvg rootvg

Determine about PP's required to create dump device.

3) Check the PV's in the rootvg

# lsvg -p rootvg

Select the PV which is having more free PP's to create dump device.

4) Create a dump device.

# mklv -y dump_device -t dump rootvg PP's PV

5) Check the dump device

# lsvg -l rootvg

6) Initialzie the Dump

# sysdumpdev -K

7) Assign the dump device as a primary dump device

# sysdumpdev -Pp /dev/dump_device

8) verify the dump device

# sysdumpdev -l

House Keeping in HMC

This section shows how to handle filesystem "/var" utilization in an HMC. Since the /var filesystem holds all the log files, performing periodic house keeping on /var would keep it in a consistent state.

Login into HMC-CLI.

1) # monhmc -r {disk|proc|swap|mem} -n #

-r :  Resource
-n : Interval to repeat the status of the resources.

2) # chhmcfs -o f { -d days | -h hours| -s size} -f filesystem

-o : Operation to be performed, "f" refers to free the filesytem.

# chhmcfs -o f -d 3

The above command cleans up the log files from all the filesystem except the last 3 days -d 3.

# chhmc -o f /var

The above command cleans up all the log files in tehe /var filesystem.

3) # monhmc -r disk

Verify the filesystem size after performing the operation.