[mythtv-users] Slighty OT: Software raid mdadm online capacity expansion (OCE) success

[Steven Adeff]

On 10/14/06, Gene Stapp <genestapp at gmail.com> wrote:
> Just thought I'd let everyone know I was able to do a raid 5 disk
> expansion in mdadm software raid with no ill effects. I used mdadm 2.5.4
> (built from source) and supposedly it is pretty safe. Following this
> page as a guide and it worked perfectly. Took about 6 hours to reshape
> the array. From 300gb x 4 raid 5 to 300gb x 5 raid 5. No lvm just an md0
> mdadm device and I was still able to make 2 simultaneous HD recordings
> and watch an HD recording while this was going on.
>
> page used as guide:
> http://scotgate.org/?p=107#comments
>
> for me the process was:
> |mdadm --add /dev/md0 /dev/sde1|
>
> then:
> |mdadm --grow /dev/md0 --raid-devices=5
>
> |to find details about your raid reshaping status use:
> cat /proc/mdstat
>
> to speed up reshaping use (fill in whatever speed you want where the
> 100000 is. Default is 10000 :
> echo -n 100000 > /proc/sys/dev/raid/speed_limit_max
>
> The only difference for xfs is to use the:
>  xfs_growfs (path to mounted raid filesystem)
>
> Hope this is helpful as I didn't see anything in the archives on this topic,
> Gene

great to hear. I've been looking at building a RAID5 array in two
parts (to spread out the costs), one of the things I was looking for
was information on how long the process takes.

Any idea what the speed_limit_max does?

-- 
Steve
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