topic Re: /etc/lvmtab differences in a MC SG cluster in Operating System - HP-UX

/etc/lvmtab differences in a MC SG cluster

Marco Shaw_1 — Fri, 16 Jan 2009 17:20:26 GMT

I had done some work to increase the size of a LV. That included adding another physical disk. It appears I missed a step or 2.

This is a 2-node MC SG cluster.

I recently tried to failover to the passive node, but the failover fails.

When I run this on both: strings /etc/lvmtab, I get 3 devices on the active, but only 2 on the passive. The disk I added is not showing on the passive.

What do I need to do to fix this?

A vgexport -m from the active, and vgimport -m from the passive? Can I do this somehow without having to umount the FS or some other service affecting set of commands?

Re: /etc/lvmtab differences in a MC SG cluster

Avinash20 — Fri, 16 Jan 2009 18:03:18 GMT

Yes, you could do a vgexport in preview mode in active mode and do a vgexport/mkdir/mknod/vgimport on the passive node where only two disk are visible in /etc/lvmtab

This will not affect any services

NOTE: The three disks you are taking about should be CLAIMED.

Re: /etc/lvmtab differences in a MC SG cluster

Avinash20 — Fri, 16 Jan 2009 18:06:41 GMT

#vgexport â p â s â m /tmp/vgXX.map /dev/vgXX
Copy the file to passive server, and login into it
# vgexport /dev/vgXX
# mkdir /dev/vgXX
# mknod /dev/vgXX/group c 64 0x0X0000
>> Same minor number (0x0X0000)
# vgimport â s â m /tmp/vgXX.map vgXX
# strings /etc/lvmtab

NOTE: Passive server is presently not having the package(belonging to the above VG) running

Re: /etc/lvmtab differences in a MC SG cluster

Avinash20 — Fri, 16 Jan 2009 18:09:12 GMT

Dont know why its not viewable
Active node:
# vgexport -p -s -m /tmp/vgXX.map /dev/vgXX
Copy the file /tmp/vgXX.map to passive server, and login into it
# vgexport /dev/vgXX
# mkdir /dev/vgXX
# mknod /dev/vgXX/group c 64 0x0X0000
>> Same minor number (0x0X0000)
# vgimport -s -m /tmp/vgXX.map vgXX
# strings /etc/lvmtab

Re: /etc/lvmtab differences in a MC SG cluster

Marco Shaw_1 — Fri, 16 Jan 2009 18:17:42 GMT

This is what I'm returned with the flags "-p -s -m":
vgexport: Volume group "/dev/vg_foo" is still active.

Is there a way to do this without taking the FS offline?

Re: /etc/lvmtab differences in a MC SG cluster

Avinash20 — Fri, 16 Jan 2009 18:23:15 GMT

Thats correct..
now the map file has been created

You have to copy that to the other node

Re: /etc/lvmtab differences in a MC SG cluster

Avinash20 — Fri, 16 Jan 2009 18:29:36 GMT

Since the vg is active, we are running vgexport in preview mode, to get the list VGID and LVM information.

For getting this information, we dont have to deactivate the VG.

Now once the map file is created, just import it to the other node.

No downtime is required

Re: /etc/lvmtab differences in a MC SG cluster

Marco Shaw_1 — Fri, 16 Jan 2009 18:33:46 GMT

Oh, OK, the message is just a warning. The file is still created.

I get this on the passive node:
vgimport: Volume group "/dev/vg_foo" already exists in the "/etc/lvmtab" file.

Yes, the VG is already in lvmtab, but now, there's an extra device that needs to be added.

Can vgimport be forced? I don't see a flag for it.

Re: /etc/lvmtab differences in a MC SG cluster

Avinash20 — Fri, 16 Jan 2009 18:44:25 GMT

# vgexport /dev/vgXX
# mkdir /dev/vgXX
# mknod /dev/vgXX/group c 64 0x0X0000
>> Same minor number (0x0X0000) as that on the other node
# vgimport -s -m /tmp/vgXX.map vgXX
# strings /etc/lvmtab

Re: /etc/lvmtab differences in a MC SG cluster

Marco Shaw_1 — Fri, 16 Jan 2009 19:07:49 GMT

But I'm getting an error about a VG already existing...

Re: /etc/lvmtab differences in a MC SG cluster

Avinash20 — Fri, 16 Jan 2009 19:12:20 GMT

Please execute vgexport first

We need to remove the vg from lvmtab and again add it

Re: /etc/lvmtab differences in a MC SG cluster

Avinash20 — Fri, 16 Jan 2009 19:15:28 GMT

On Passive node

# vgexport /dev/vg_foo
# mkdir /dev/vg_foo
# mknod /dev/vg_foo/group c 64 0x0X0000
>> "0x0X0000" This is a minor number and should be same as that on the other node
You could find the minor on active node via
ll /dev/vg_foo/group
check for value 0x0X0000 << Here X is a numeric value
# vgimport -s -m /tmp/vgXX.map vgXX
# strings /etc/lvmtab

Re: /etc/lvmtab differences in a MC SG cluster

Avinash20 — Sun, 18 Jan 2009 15:31:33 GMT

Hi Mate,

Did you forget to assign points to this post :)

Re: /etc/lvmtab differences in a MC SG cluster

Avinash20 — Tue, 20 Jan 2009 04:21:31 GMT

Hi Marco,

Are you still facing some other issue.
If not, please assign the point.

Re: /etc/lvmtab differences in a MC SG cluster

Marco Shaw_1 — Tue, 20 Jan 2009 13:23:58 GMT

Sorry, I was busy. I need to research this:

root@[foo]/etc> vgimport -s -m /tmp/vg_bar.map vg_bar
Warning: Logical Volume number "7" found on physical volume not found in "/tmp/vg_bar.map".

LVOL7 exists on the active node currently and is valid.

strings /etc/lvmtab is giving me one extra disk for vg_bar which I'll also need to research.

Re: /etc/lvmtab differences in a MC SG cluster

Avinash20 — Tue, 20 Jan 2009 15:33:10 GMT

Hi,

Check
# strings /tmp/vg_bar.map

Check if this contains lvol7
Compare /tmp/vg_bar.map on both the nodes