topic Re: Add logical volume to VG in cluster in Operating System - HP-UX

Add logical volume to VG in cluster

Weertman — Wed, 18 Mar 2009 05:48:38 GMT

When I add a logical volume to a vg in a package do I need to do the export and import?
It is a raw volume so no mkfs is needed.

Re: Add logical volume to VG in cluster

Sharma Sanjeev — Wed, 18 Mar 2009 06:14:31 GMT

Hi

Yes, u need to export and import it on another node with new map file

Rergards
Sanjeev

Re: Add logical volume to VG in cluster

Avinash20 — Wed, 18 Mar 2009 06:21:24 GMT

Yes, it is required.

The device file /dev//* needs to be available on the other node also

Hence you need to do a vgexport -p on one node and on the other node, vgexport, mkdir,mknod, vgimport..

Please assign points

Re: Add logical volume to VG in cluster

Weertman — Wed, 18 Mar 2009 07:14:06 GMT

when you omit that can that cause volume corruption in case of fail-over?

Re: Add logical volume to VG in cluster

yulianto piyut — Wed, 18 Mar 2009 07:19:29 GMT

absolutely, YES! you must vgexport and vgimport to the other node and you must edit your control file (*.cntl) in your cluster configuration and add your new LV, for ex:

LV[0]=/dev/vgbea/lvbea; FS[0]=/apps/bea; FS_MOUNT_OPT[0]="-o rw"; FS_UMOUNT_OPT[
0]=""; FS_FSCK_OPT[0]="";FS_TYPE[0]="vxfs"

Re: Add logical volume to VG in cluster

Avinash20 — Wed, 18 Mar 2009 07:41:44 GMT

"when you omit that can that cause volume corruption in case of fail-over?"

Yes, that why we are doing vgexport in preview mode on one server and doing a vgimport on the other node

vgimport wont work if the vg is already there in lvmtab, hence we need to export and import it again ..

Re: Add logical volume to VG in cluster

Weertman — Wed, 18 Mar 2009 08:20:23 GMT

what is the correct import command?

Re: Add logical volume to VG in cluster

Johnson Punniyalingam — Wed, 18 Mar 2009 08:24:29 GMT

Example:-

On the other node:
1. Export the VG
>>>vgexport /dev/vgxx

2. Recreate the directory
>>>>mkdir -p /dev/vgxx

3. Recreate the VG group file
>>>mknod /dev/vgxx/group c 64 0xMM0000
where MM is a unique identifier (ex 01 for vg01)

4. Preview the vgimport to check for any possible error
>>>>vgimport -pvs -m /dev/vgxx
where mapfile is the one copied from the first node

5. If no error, remove the preview mode
>>>>vgimport -vs -m /dev/vgxx

6. Activate in share mode
>>>>vgchange -a s /dev/vgxx

Thanks,
Johnson

Re: Add logical volume to VG in cluster

Weertman — Wed, 18 Mar 2009 08:35:58 GMT

vgchange -a s /dev/vg02
vgchange: Volume group "/dev/vg02" does not exist in the "/etc/lvmtab" file.

Re: Add logical volume to VG in cluster

Johnson Punniyalingam — Wed, 18 Mar 2009 08:46:10 GMT

>>vgchange -a s /dev/vg02
vgchange: Volume group "/dev/vg02" does not exist in the "/etc/lvmtab" file.<<

what is vgname did you import on the other node..?

Thanks,
Johnson

Re: Add logical volume to VG in cluster

Weertman — Wed, 18 Mar 2009 11:52:57 GMT

Also vg02

Re: Add logical volume to VG in cluster

Duncan Edmonstone — Wed, 18 Mar 2009 11:59:41 GMT

you only run "vgchange -a s ..." if this is a SHARED logical volume used with SLVM (usually as part of a RAC cluster). If this is just a standard Serviceguard cluster where a logical volume is only ever active on one node in the cluster at any one time, you can omit this step.

HTH

Duncan

Re: Add logical volume to VG in cluster

Ganesan R — Wed, 18 Mar 2009 12:14:03 GMT

Hi,

Follow this steps. Assuming you are creating lv on VG02 and it is currently activated on node1

on node1

Create the logical volume as per LVM commands. After creation,
#vgexport -p -v -m /tmp/vg02.map vg02
It will just create a map file /tmp/vg02.map

Copy this map file to second node.(node2)

on node2. (Assuming VG02 is not activated here)

Note down the minor number of vg02
#vgexport /dev/vg02
#mkdir /dev/vg02
#mknod /dev/vg02/group c 64 0x020000
#vgimport -v -m /tmp/vg02.map vg02

Now the necessary devices files will be created on node2 as well. So when the package moves here all the lv's including new lv get mounted.

Not that these steps doesn't include the modifications of package control file. you need take care of that seperately.

Re: Add logical volume to VG in cluster

Sharma Sanjeev — Wed, 18 Mar 2009 12:18:30 GMT

Hi

If still u want to see your VG on another node than u can activate it as readonly.

vgchange -a r /dev/vg02

Regards
Sanjeev

Re: Add logical volume to VG in cluster

Weertman — Thu, 19 Mar 2009 11:01:26 GMT

shouldn't it be:
vgimport -v -m /tmp/vg02.map vg02 /dev/dsk/c16t0d5

There is no hw info in the map file.

that works ok

Re: Add logical volume to VG in cluster

Sharma Sanjeev — Thu, 19 Mar 2009 11:10:42 GMT

Hi

Best way is

on 1st node
vgexport -p -m /tmp/mapfile -f /tmp/diskfile /dev/vg00

than copy mapfile and disk file to another node

than on 2nd node
vgexport vg02
mknod ( minor number should be same as 1st node vg02 )
vgimport -m /tmp/mapfile -f /tmp/diskfile /dev/vg02

if u want to activate VG on 2nd node as read only

vgchange -a r /dev/vg02

Regards
Sanjeev

Re: Add logical volume to VG in cluster

Weertman — Fri, 20 Mar 2009 07:28:37 GMT

What is the destination node has a different device name?

Re: Add logical volume to VG in cluster

Sharma Sanjeev — Fri, 20 Mar 2009 07:39:04 GMT

Hi Again

Than u need to import with device name.

But generally The nodes in Cluster having same device name

Regards
Sanjeev

Re: Add logical volume to VG in cluster

Duncan Edmonstone — Fri, 20 Mar 2009 07:48:09 GMT

...seems to be a lot of poor advice being handed out on this thread...

first off, when you are running the vgexport on your primary node to generate the map file, you need to make nsure you include the "-s" option on the vgexport. This will ensure that as well as the lvol names, the volume group ID is also writrten to the map file (think of the volume group ID or VGID as like a disk signature)

Then when importing the volume group on the other node use the "-s" option on the vgimport and the vgimport command will scan all the disks visible to the system and look for that VGID - that way it knows what disks need to be part of the volume group and you don't have to list them on the command line.

As for the point about device files being the same on all cluster nodes. In my experience they are different as often as they are the same. Serviceguard really doesn't care if a LUN is seen as c3t5d0 on one node and c7t5d0 on another node - it can cope with that without a problem.

HTH

Duncan

Re: Add logical volume to VG in cluster

Duncan Edmonstone — Fri, 20 Mar 2009 07:51:56 GMT

Ganesan's post was closest to correct - I've altered it slightly (I don't know what your VG is called or what VG minor numbers you use so you'll need to adjust those for your own system):

on node1

Create the logical volume as per LVM commands. After creation,
#vgexport -p -s -v -m /tmp/vg02.map vg02
It will just create a map file /tmp/vg02.map

Copy this map file to second node.(node2)

on node2. (Assuming VG02 is not activated here)

Note down the minor number of vg02
#vgexport /dev/vg02
#mkdir /dev/vg02
#mknod /dev/vg02/group c 64 0x020000
#vgimport -v -s -m /tmp/vg02.map vg02

It will take a little longer as it has to scan all the disks on the system, but should work.

HTH

Duncan