mirrorvg command like in AIX

Latest response

I would like to see a mirrorvg command like in AIX that would allow us to make a bootable mirror of the root disk.

We are running into an issue with root being on a drive that is to small and we need to increase /var but no space is left. 

 

I know I can request another drive and add it to the rootvg and increase/resize the lv/fs as needed.

I like to keep rootvg on one disk not span multiple disks.

 

In AIX I can request a bigger drive.. mirror the rootvg... do some other commands (bosboot/bootlist) once its mirrored and then unmirror off the smaller disk and remove it. The system will boot just fine.

 

It would be nice to see this function in RHEL.

As of now I am being told I can only mirror the data disks not the rootvg and have it bootable.

This would be handy to use for cloning and updating to a new version of RHEL from say 5 to 6 or 7 etc. That way you have a recover point should you need it.

 

Might be good feature for patching a system too.

 

Clone then patch and have a fall back point if the patch breaks something.

 

We do this all the time on AIX.

Responses

In AIX I can request a bigger drive.. mirror the rootvg... do some other commands (bosboot/bootlist) once its mirrored and then unmirror off the smaller disk and remove it. The system will boot just fine.

I haven't actually tested this, but it looks to me like this can already be done.

 

Request a bigger disk, add it to the rootvg, mirror the LV, remove the PV from the VG and you should be done.

 

Names shouldn't change, so your system should be able to boot fine.

 

Only exception might be the bootloader, but this is usually on a seperate partition. If you want, you could dd the first 446 bytes over for the stage1 bootloader.

Interesting topic...I suppose ive never had the need for this, I boot all of my physical RHEL servers off of a SAN so I just use native SAN replays (snapshots) for recovery points and quick DR with boot from SAN copies of the boot LUN's.

I have been using mirrorvg all the time on AIX.