Re: Howto avoid full re-sync

[NeilBrown <neilb@suse.de>]

[-- Attachment #1: Type: text/plain, Size: 2420 bytes --]

On Mon, 10 Sep 2012 09:11:54 +1000 Adam Goryachev
<adam@websitemanagers.com.au> wrote:

> On 09/07/2012 07:41 PM, Ralf Müller wrote:
> > Am 07.09.2012 um 06:41 schrieb Adam Goryachev:
> >
> >> I have a MD raid6 with 5 drives, and every now and then one (random)
> >> drive will fail. I've done all sorts of checks, and the drive is
> >> actually working fine, so I suspect an issue with the Linux driver
> >> and/or SATA controller (onboard).
> >>
> >> It isn't really relevant to the question, but I'll run through the sata
> >> stuff, in case anyone can point out a simple solution to stop this from
> >> happening (yes, a new server is on the way, but with budgets etc, that
> >> could be some time away. This issue has happened for years, but we are
> >> becoming more active with these failures now).
> >>
> >> 00:0e.0 IDE interface: nVidia Corporation MCP51 Serial ATA Controller
> >> (rev a1)
> >> 00:0f.0 IDE interface: nVidia Corporation MCP51 Serial ATA Controller
> >> (rev a1)
> >> 01:07.0 RAID bus controller: Silicon Image, Inc. Adaptec AAR-1210SA SATA
> >> HostRAID Controller (rev 02)
> >>
> >> cat /proc/mdstat
> >> Personalities : [raid1] [raid6] [raid5] [raid4]
> >> md2 : active raid6 sdh1[5] sdg1[4] sdf1[0] sdd1[6](F) sde1[2] sda1[1]
> >>       5860535808 blocks level 6, 64k chunk, algorithm 2 [5/4] [UUU_U]
> >>       [>....................]  recovery =  1.4% (28663240/1953511936)
> >> finish=486.5min speed=65938K/sec
> >>
> >>
> >>
> >> Since I know sdh is actually almost up to date, is there some way to
> >> re-add it, and only have to sync the portions of the disk which have
> >> changed?
> >
> > Besides all the stuff about fix your server, a raid is not a backup and you risk your data - simply add a write intent bitmap:
> >
> > # mdadm /dev/md2 --grow bitmap=internal
> >
> mdadm /dev/md2 --grow bitmap=internal
> mdadm: can only add devices to linear arrays

Check the man page....


 mdadm /dev/md2 --grow --bitmap=internal

NeilBrown


> 
> md2 is raid6:
> md2 : active raid6 sdh1[3] sdg1[4] sdf1[0] sde1[2] sda1[1]
>        5860535808 blocks level 6, 64k chunk, algorithm 2 [5/5] [UUUUU]
> 
> Regards,
> Adam
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html


[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 828 bytes --]