Booting RH from LVM Mirror copy on SAN disk

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Rootvg is installed on the local disk with mirror copy (LVM) on the SAN disk. If it possible to break the mirror and boot from SAN disk mirror to enable to have local disk configured as RAID are controller level. Any suggestion would be appreciated

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Malkeet,

I am confused as to why you are using LVM to do the mirroring if you have SAN infrastructure? does your SAN support mirroring disks?

I have booted a VM in a DR event from a remotely mirrored SAN disk but this was mirrored at the disk level by the SAN hardware, underneath LVM.

One issue I can foresee you having is that the /boot partition is likely not in LVM, so will not be part of the LVM mirror. This will mean there will be some configuration required to boot the mirrored image (you will need to create a /boot partition).

Hey PixelDrift.NET -
One reason folks may use LVM mirroring is to mimic functionality that Solaris had back in the day with ABE (Alternate Boot Environment) and LU (Live Upgrade). And a brilliant use case was to split the mirror (after you quiesce the filesystem), patch the remaining running environment (or patch the split mirror) and resync once you rebooted and validated everything was working.

Hey PixelDrift.NET

Thanks.

When the physical server (IBM system x3850) were delivered there was some issue with local RAID controller. The o/s was installed on a local disk. Later on the controller issue was resolved but to configure the h/w RAID would require the disk to be initialized. The practice to have the local disk configured in h/w RAID1 for rootvg.

MAlkeet

Malkeet,

Thanks, now I see what you are doing! :D

I would look at options to clone this at a lower level than LVM (ie. disk level). I would suggest even a basic 'dd' if you can assume the disk geometries are going to be the same (as it's RAID1) but it's tedious if there a problems restoring the disk image. If using DD I would suggest mounting the SAN LUN and configuring a filesystem and saving the dd image as a file.

Do you have an enterprise backup tool you can use to backup/bare metal restore? or even carry out a file level backup and restore over a base installation installed on the RAID when it is built?

Another option may be an imaging tool like http://clonezilla.org/ to save an image file of the entire disk, it handles geometry changes (target bigger than source) more gracefully than a straight 'dd'... it has limitations too though eg. it's unable to capture mounted partitions.. so you will need to boot from a LiveCD.

In answer to your LVM question, I am sure it is possible but I believe /boot not being on LVM will complicate the restore.

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