Re: Raid 5 to 6 migration

[Phil Turmel <philip@turmel.org>]

On 02/05/2013 05:36 AM, Dominique wrote:
> 
> Thanks for the detailled answer. I read through all of it to identify
> what I did not understood before starting. I have a few clarificacions
> for you and a few questions.
> 
> Yes, that's the way my console looks like. I usually don't have problem
> with UTF8 output (i.e. not garbled), I figured it was the result of the
> lsdrv.... Nasty to read, but it's all there.

Thanks for the report.  I'll have to set up a VM with your distro and
play a bit.

> I am running Ubuntu 12.04.1 server on this relatively new raid5 setup.
> I think I understood most of the reshaping instructions, but I need to
> clarify your point related to the timeout. I tried to execute it in a
> simple bash file and got stopped at the beginning just for the lack of a
> timeoutfile?
> 
> After looking for it, I realised that sd[abcdef] were all symlinks
> pointing to another part of the system, where there is no driver
> directory. After browsing, i figured out that /sys/block/sda/device did
> led to a timeout file. Can you please confirm, it is the one we want ?

Yes, sorry.  Typo on my part.

> A last point I need to clarify: is the reshaping (although long) data
> destructive (backup will be done in all cases)?

The reshape may need a small backup file for critical section(s).  If it
does, it will refuse to proceed until you specify one with
"--backup-file=..." in the "--grow" operation.  If your system crashes
during the reshape, be sure to specify the same backup file when
re-assembling.

But yes, redundancy is maintained throughout the reshape.

> Thanks,

You're welcome.

Phil