topic Re: Linux host data/server migration in Operating System - Linux

Linux host data/server migration

Taylor Lewick_2 — Tue, 18 Jul 2006 08:19:02 GMT

Hi all. We are in the middle of a data center migration. We are physically moving our servers and migrating data from our old data center to new by copying from an old EMC disk array to a new ECM disk array using SRDF.

We have already migrated several HP-UX hosts using LVM and Veritas Volume Manager.

For migrating the data on the HP-UX hosts we used the vgexport -s -v -m mapfile /dev/vg0#
command. The -s marked a signature on the disks so that even though the hardware path changed, vgimport new to look for the signature of the disk and bring in the disks into the correct volume group. It worked perfectly.

My question is, we are doing the same thing on some Linux hosts.

The current SAN connected filesystems are not using LVM. We have zoned in the new storage, (we are extending the fabirc so the hosts can see old and new arrays at same time) and I have configured those disks using lvm.

Will vgexport/vgimport on RedHat using LVM2 work the same way it does on HP-UX? I know you can't tell the vgexport to use a signature to identify which disk is in which volume group, but does it store that information automatically?

Re: Linux host data/server migration

Steven E. Protter — Tue, 18 Jul 2006 11:43:29 GMT

Shalom,

vgexport/vgimport is SUPPOSED to work on Linux LVM2 as it does on HP-UX.

Note that LVM on Linux was not a code port, it was a feature and functionality port.

Therefore you should test that it ACTUALLY works.

Do it with a play system first.

SEP

Re: Linux host data/server migration

Ivan Ferreira — Tue, 18 Jul 2006 11:47:24 GMT

Hi Taylor, that it's possible, check these links:

http://www.die.net/doc/linux/HOWTO/LVM-HOWTO-16.html
http://www.linux.com/howtos/LVM-HOWTO/recipemovevgtonewsys.shtml

Re: Linux host data/server migration

Taylor Lewick_2 — Tue, 18 Jul 2006 13:50:57 GMT

I tested it, I can pleasantly say it did work.

Here is what we did for test. We zoned/lun masked the same LUN to two different servers. I pvcreated the LUN on one, made a test volume group and mkfs on it, then mounted it and copied some data to it.

unmount
vgchange -a n vgtest
vgexport vgtest

On other system
vgimport vgtest
vgchange -a y vgtest
mount /dev/vgtes/lvol1 /test_dir

Worked great. Pretty impressed.

Thanks all...

Taylor