VPars - migrating the root VG/PV to new PV on a new array - what are the steps?

[tazhasan]

Hi

We are migrating from on 3par to another and among the hosts attached are some rx8640's running vpars.

I just need some clarification on what steps need to be taken as not only are vpars involved, but serviceguard as ll.

Is it better to mirror onto a 2nd pv with lvextend, or straight pvmove?

Any ideas would be mush apprciated.

Regards

Tariq

[PSPrakash]

Hello

Its laways good to use LVM-Mirror for this kind of migration. Once you have verified/confimred  you may reduce the old array form the LV/VG.

Regards
PSP

[rachelgomez_123]

If you want to migrate the data to a new disk, do the following steps. Otherwise, continue with step 2.
Check that the disk is recognizable by the system and available by typing:
lsdev -Cc disk

The output resembles the following:
hdisk0 Available 10-60-00-8,0 16 Bit LVD SCSI Disk Drive
hdisk1 Available 10-60-00-9,0 16 Bit LVD SCSI Disk Drive
hdisk2 Available 10-60-00-11,0 16 Bit LVD SCSI Disk Drive

If the disk is listed and in the available state, check that it does not belong to another volume group by typing:
lspv

The output looks similar to the following:
hdisk0 0004234583aa7879 rootvg active
hdisk1 00042345e05603c1 none active
hdisk2 00083772caa7896e imagesvg active

In the example, hdisk1 can be used as a destination disk because the third field shows that it is not being used by a volume group.
If the new disk is not listed or unavailable, you need to configure the disk or logical volume storage.

Add the new disk to the volume group by typing:
extendvg VGName diskname

Where VGName is the name of your volume group and diskname is the name of the new disk. In the example shown in the previous step, diskname would be replaced by hdisk1.
The source and destination physical volumes must be in the same volume group. To determine whether both physical volumes are in the volume group, type:
lsvg -p VGname

Where VGname is the name of your volume group. The output for a root volume group looks similar to the following:
rootvg:
PV_NAME PV STATE TOTAL PPs FREE PPs FREE DISTRIBUTION
hdisk0 active 542 85 00..00..00..26..59
hdisk1 active 542 306 00..00..00..00..06

Note the number of FREE PPs.
Check that you have enough room on the target disk for the source that you want to move:
Determine the number of physical partitions on the source disk by typing:
lspv SourceDiskName | grep "USED PPs"

Where SourceDiskName is of the name of the source disk, for example, hdisk0. The output looks similar to the following:
USED PPs: 159 (636 megabytes)

In this example, you need 159 FREE PPs on the destination disk to successfully complete the migration.
Compare the number of USED PPs from the source disk with the number of FREE PPs on the destination disk or disks (step 2). If the number of FREE PPs is larger than the number of USED PPs, you have enough space for the migration.
Follow this step only if you are migrating data from a disk in the rootvg volume group.
If you are migrating data from a disk in a user-defined volume group, proceed to step 5.
Check to see if the boot logical volume (hd5) is on the source disk by typing:
lspv -l SourceDiskNumber | grep hd5

If you get no output, the boot logical volume is not located on the source disk. Continue to step 5.
If you get output similar to the following:
hd5 2 2 02..00..00..00..00 /blv

then run the following command:
migratepv -l hd5 SourceDiskName DestinationDiskName

You will receive a message warning you to perform the bosboot command on the destination disk. You must also perform a mkboot -c command to clear the boot record on the source. Type the following sequence of commands:
bosboot -a -d /dev/DestinationDiskName
bootlist -m normal DestinationDiskName
mkboot -c -d /dev/SourceDiskName

Migrate your data by typing the following SMIT fast path:
smit migratepv

List the physical volumes, and select the source physical volume you examined previously.
Go to the DESTINATION physical volume field. If you accept the default, all the physical volumes in the volume group are available for the transfer. Otherwise, select one or more disks with adequate space for the partitions you are moving (from step 4).
If you wish, go to the Move only data belonging to this LOGICAL VOLUME field, and list and select a logical volume. You move only the physical partitions allocated to the logical volume specified that are located on the physical volume selected as the source physical volume.
Press Enter to move the physical partitions.
At this point, the data now resides on the new (destination) disk. The original (source) disk, however, remains in the volume group. If the disk is still reliable, you could continue to use it as a hot spare disk. Especially when a disk is failing, it is advisable to do the following steps:
To remove the source disk from the volume group, type:
reducevg VGNname SourceDiskName

To physically remove the source disk from the system, type:
rmdev -l SourceDiskName -d

Regards,

Rachel Gomez