[lug] replace sw raid mirror with larger disks (migrate)

[Orion Poplawski]

On 12/09/2011 04:14 PM, karl horlen wrote:
> does anybody know if / how to migrate a *live* linux sw raid 1 mirror to larger drives?
>
> my system has 80 GB sw mirror (installed a couple of years ago) but i want to swap them out with 1 Ts.  would probably be a useful exercise to do if it can be done successfully vs simply reinstalling from scratch and restoring from backups.  fyi, i only have 2 drive bays so i'm going to have to somehow shutdown one half of the array and migrate the live half to the the newly installed drive.

man mdadm?

Hot swap drives or no?  Easier with hot swap, but probably doable without. 
Fail and remove one side of the mirror.  Pull and replace the drive. 
Partition the new drive and add it to the array.  Let the array sync.  Do the 
same thing with the other drive.  Then you should be able to do:

mdadm --grow /dev/md# --size=max

>
> otoh, since this is a centos 5 system, perhaps it would be best to upgrade to centos 6 fresh now while i'm taking the system down and restore data from backups.  anybody have thoughts on stability of centos 6 at this point?  perhaps i bite the bullet now and just reinstall 6 from scratch b/c i'm just going to have to do this anyway.

Probably.  You can install into existing raid/lvm devices, but the default 
mdadm raid format has changed from EL5 to EL6 and you are probably better off 
getting the new format as well.

-- 
Orion Poplawski
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