From: NeilBrown <neilb@suse.de>
To: Larkin Lowrey <llowrey@nuclearwinter.com>
Cc: linux-raid <linux-raid@vger.kernel.org>
Subject: Re: Recovering raid6 with 3 of 12 disks
Date: Thu, 15 Mar 2012 06:26:11 +1100 [thread overview]
Message-ID: <20120315062611.0ff6bcc0@notabene.brown> (raw)
In-Reply-To: <4F60E371.20609@nuclearwinter.com>
[-- Attachment #1: Type: text/plain, Size: 21489 bytes --]
On Wed, 14 Mar 2012 13:29:05 -0500 Larkin Lowrey <llowrey@nuclearwinter.com>
wrote:
> Thanks to mvsas not hanlding drives in standby (spun down) well, 9 of my
> drives got kicked out of the array. Fortunately, the logical volume on
> that array was not mounted so the data on the array should be fine.
>
> Needless to say, I can't assemble the array with only 3 disks. My best
> understanding is that I need to re-create the array with --assume-clean
> and that I need to specify the drives in their original order (and not
> use any shell globbing like /dev/sd[k-r]).
You should be able to assemble the array if you add '--force'.
>
> Q1: The original metadata was 0.90. I've read that it would be safe to
> re-create the array with 1.0 metadata because the superblocks are stored
> at the same location and are smaller than 0.90 superblocks. Please confirm.
correct.
>
> Q2: Given the output of mdadm -E the tail of this e-mail, would the
> command below be correct?
>
> mdadm --assemble /dev/md2 --assume-clean --level=6 --chunk=128
> --raid-devices=12 --metadata=1.0 /dev/sdn2 /dev/sdk2 /dev/sdl2 /dev/sdm2
> /dev/sdy1 /dev/sdp2 /dev/sdo2 /dev/sdr2 /dev/sdq2 /dev/sdw1 /dev/sdx1
> /dev/sdz1
I didn't check all the devices, but the first one is definitely /dev/sdn2, so
you used the right algorithm.
>
> Q3: To verify that I have the drives in order I should be able to run a
> 'check' and watch the missmatch count. If the count is substantially
> non-zero then I have the drives in the wrong order. Would it be safe to
> 'try again' until I get the right combo?
Yes - it wouldn't help for RAID5, but it would for RAID6.
NeilBrown
>
> Thank you for your attention and any assistance you can offer.
>
> --Larkin
>
> /dev/sdw1:
> Magic : a92b4efc
> Version : 0.90.00
> UUID : 08b30a7c:151f719c:e2349310:51678405
> Creation Time : Fri May 7 21:44:25 2010
> Raid Level : raid6
> Used Dev Size : 664191232 (633.42 GiB 680.13 GB)
> Array Size : 6641912320 (6334.22 GiB 6801.32 GB)
> Raid Devices : 12
> Total Devices : 11
> Preferred Minor : 2
>
> Update Time : Wed Mar 14 03:16:48 2012
> State : clean
> Active Devices : 3
> Working Devices : 3
> Failed Devices : 8
> Spare Devices : 0
> Checksum : bdaa1605 - correct
> Events : 1647040
>
> Layout : left-symmetric
> Chunk Size : 128K
>
> Number Major Minor RaidDevice State
> this 9 65 113 9 active sync /dev/sdx1
>
> 0 0 0 0 0 removed
> 1 1 0 0 1 faulty removed
> 2 2 0 0 2 faulty removed
> 3 3 0 0 3 faulty removed
> 4 4 0 0 4 faulty removed
> 5 5 0 0 5 faulty removed
> 6 6 0 0 6 faulty removed
> 7 7 0 0 7 faulty removed
> 8 8 0 0 8 faulty removed
> 9 9 65 113 9 active sync /dev/sdx1
> 10 10 65 129 10 active sync /dev/sdy1
> 11 11 65 97 11 active sync /dev/sdw1
> /dev/sdx1:
> Magic : a92b4efc
> Version : 0.90.00
> UUID : 08b30a7c:151f719c:e2349310:51678405
> Creation Time : Fri May 7 21:44:25 2010
> Raid Level : raid6
> Used Dev Size : 664191232 (633.42 GiB 680.13 GB)
> Array Size : 6641912320 (6334.22 GiB 6801.32 GB)
> Raid Devices : 12
> Total Devices : 11
> Preferred Minor : 2
>
> Update Time : Wed Mar 14 03:16:48 2012
> State : clean
> Active Devices : 3
> Working Devices : 3
> Failed Devices : 8
> Spare Devices : 0
> Checksum : bdaa1617 - correct
> Events : 1647040
>
> Layout : left-symmetric
> Chunk Size : 128K
>
> Number Major Minor RaidDevice State
> this 10 65 129 10 active sync /dev/sdy1
>
> 0 0 0 0 0 removed
> 1 1 0 0 1 faulty removed
> 2 2 0 0 2 faulty removed
> 3 3 0 0 3 faulty removed
> 4 4 0 0 4 faulty removed
> 5 5 0 0 5 faulty removed
> 6 6 0 0 6 faulty removed
> 7 7 0 0 7 faulty removed
> 8 8 0 0 8 faulty removed
> 9 9 65 113 9 active sync /dev/sdx1
> 10 10 65 129 10 active sync /dev/sdy1
> 11 11 65 97 11 active sync /dev/sdw1
> /dev/sdy1:
> Magic : a92b4efc
> Version : 0.90.00
> UUID : 08b30a7c:151f719c:e2349310:51678405
> Creation Time : Fri May 7 21:44:25 2010
> Raid Level : raid6
> Used Dev Size : 664191232 (633.42 GiB 680.13 GB)
> Array Size : 6641912320 (6334.22 GiB 6801.32 GB)
> Raid Devices : 12
> Total Devices : 12
> Preferred Minor : 2
>
> Update Time : Tue Mar 13 21:46:30 2012
> State : clean
> Active Devices : 12
> Working Devices : 12
> Failed Devices : 0
> Spare Devices : 0
> Checksum : bda9c7df - correct
> Events : 1647037
>
> Layout : left-symmetric
> Chunk Size : 128K
>
> Number Major Minor RaidDevice State
> this 4 65 145 4 active sync /dev/sdz1
>
> 0 0 65 18 0 active sync /dev/sdr2
> 1 1 8 226 1 active sync /dev/sdo2
> 2 2 8 242 2 active sync /dev/sdp2
> 3 3 65 2 3 active sync /dev/sdq2
> 4 4 65 145 4 active sync /dev/sdz1
> 5 5 8 178 5 active sync /dev/sdl2
> 6 6 8 162 6 active sync /dev/sdk2
> 7 7 8 210 7 active sync /dev/sdn2
> 8 8 8 194 8 active sync /dev/sdm2
> 9 9 65 113 9 active sync /dev/sdx1
> 10 10 65 129 10 active sync /dev/sdy1
> 11 11 65 97 11 active sync /dev/sdw1
> /dev/sdz1:
> Magic : a92b4efc
> Version : 0.90.00
> UUID : 08b30a7c:151f719c:e2349310:51678405
> Creation Time : Fri May 7 21:44:25 2010
> Raid Level : raid6
> Used Dev Size : 664191232 (633.42 GiB 680.13 GB)
> Array Size : 6641912320 (6334.22 GiB 6801.32 GB)
> Raid Devices : 12
> Total Devices : 11
> Preferred Minor : 2
>
> Update Time : Wed Mar 14 03:16:48 2012
> State : clean
> Active Devices : 3
> Working Devices : 3
> Failed Devices : 8
> Spare Devices : 0
> Checksum : bdaa15f9 - correct
> Events : 1647040
>
> Layout : left-symmetric
> Chunk Size : 128K
>
> Number Major Minor RaidDevice State
> this 11 65 97 11 active sync /dev/sdw1
>
> 0 0 0 0 0 removed
> 1 1 0 0 1 faulty removed
> 2 2 0 0 2 faulty removed
> 3 3 0 0 3 faulty removed
> 4 4 0 0 4 faulty removed
> 5 5 0 0 5 faulty removed
> 6 6 0 0 6 faulty removed
> 7 7 0 0 7 faulty removed
> 8 8 0 0 8 faulty removed
> 9 9 65 113 9 active sync /dev/sdx1
> 10 10 65 129 10 active sync /dev/sdy1
> 11 11 65 97 11 active sync /dev/sdw1
> /dev/sdk2:
> Magic : a92b4efc
> Version : 0.90.00
> UUID : 08b30a7c:151f719c:e2349310:51678405
> Creation Time : Fri May 7 21:44:25 2010
> Raid Level : raid6
> Used Dev Size : 664191232 (633.42 GiB 680.13 GB)
> Array Size : 6641912320 (6334.22 GiB 6801.32 GB)
> Raid Devices : 12
> Total Devices : 12
> Preferred Minor : 2
>
> Update Time : Tue Mar 13 21:46:30 2012
> State : clean
> Active Devices : 12
> Working Devices : 12
> Failed Devices : 0
> Spare Devices : 0
> Checksum : bda9c7f1 - correct
> Events : 1647037
>
> Layout : left-symmetric
> Chunk Size : 128K
>
> Number Major Minor RaidDevice State
> this 1 8 226 1 active sync /dev/sdo2
>
> 0 0 65 18 0 active sync /dev/sdr2
> 1 1 8 226 1 active sync /dev/sdo2
> 2 2 8 242 2 active sync /dev/sdp2
> 3 3 65 2 3 active sync /dev/sdq2
> 4 4 65 145 4 active sync /dev/sdz1
> 5 5 8 178 5 active sync /dev/sdl2
> 6 6 8 162 6 active sync /dev/sdk2
> 7 7 8 210 7 active sync /dev/sdn2
> 8 8 8 194 8 active sync /dev/sdm2
> 9 9 65 113 9 active sync /dev/sdx1
> 10 10 65 129 10 active sync /dev/sdy1
> 11 11 65 97 11 active sync /dev/sdw1
> /dev/sdl2:
> Magic : a92b4efc
> Version : 0.90.00
> UUID : 08b30a7c:151f719c:e2349310:51678405
> Creation Time : Fri May 7 21:44:25 2010
> Raid Level : raid6
> Used Dev Size : 664191232 (633.42 GiB 680.13 GB)
> Array Size : 6641912320 (6334.22 GiB 6801.32 GB)
> Raid Devices : 12
> Total Devices : 12
> Preferred Minor : 2
>
> Update Time : Tue Mar 13 21:46:30 2012
> State : clean
> Active Devices : 12
> Working Devices : 12
> Failed Devices : 0
> Spare Devices : 0
> Checksum : bda9c803 - correct
> Events : 1647037
>
> Layout : left-symmetric
> Chunk Size : 128K
>
> Number Major Minor RaidDevice State
> this 2 8 242 2 active sync /dev/sdp2
>
> 0 0 65 18 0 active sync /dev/sdr2
> 1 1 8 226 1 active sync /dev/sdo2
> 2 2 8 242 2 active sync /dev/sdp2
> 3 3 65 2 3 active sync /dev/sdq2
> 4 4 65 145 4 active sync /dev/sdz1
> 5 5 8 178 5 active sync /dev/sdl2
> 6 6 8 162 6 active sync /dev/sdk2
> 7 7 8 210 7 active sync /dev/sdn2
> 8 8 8 194 8 active sync /dev/sdm2
> 9 9 65 113 9 active sync /dev/sdx1
> 10 10 65 129 10 active sync /dev/sdy1
> 11 11 65 97 11 active sync /dev/sdw1
> /dev/sdm2:
> Magic : a92b4efc
> Version : 0.90.00
> UUID : 08b30a7c:151f719c:e2349310:51678405
> Creation Time : Fri May 7 21:44:25 2010
> Raid Level : raid6
> Used Dev Size : 664191232 (633.42 GiB 680.13 GB)
> Array Size : 6641912320 (6334.22 GiB 6801.32 GB)
> Raid Devices : 12
> Total Devices : 12
> Preferred Minor : 2
>
> Update Time : Tue Mar 13 21:46:30 2012
> State : clean
> Active Devices : 12
> Working Devices : 12
> Failed Devices : 0
> Spare Devices : 0
> Checksum : bda9c74e - correct
> Events : 1647037
>
> Layout : left-symmetric
> Chunk Size : 128K
>
> Number Major Minor RaidDevice State
> this 3 65 2 3 active sync /dev/sdq2
>
> 0 0 65 18 0 active sync /dev/sdr2
> 1 1 8 226 1 active sync /dev/sdo2
> 2 2 8 242 2 active sync /dev/sdp2
> 3 3 65 2 3 active sync /dev/sdq2
> 4 4 65 145 4 active sync /dev/sdz1
> 5 5 8 178 5 active sync /dev/sdl2
> 6 6 8 162 6 active sync /dev/sdk2
> 7 7 8 210 7 active sync /dev/sdn2
> 8 8 8 194 8 active sync /dev/sdm2
> 9 9 65 113 9 active sync /dev/sdx1
> 10 10 65 129 10 active sync /dev/sdy1
> 11 11 65 97 11 active sync /dev/sdw1
> /dev/sdn2:
> Magic : a92b4efc
> Version : 0.90.00
> UUID : 08b30a7c:151f719c:e2349310:51678405
> Creation Time : Fri May 7 21:44:25 2010
> Raid Level : raid6
> Used Dev Size : 664191232 (633.42 GiB 680.13 GB)
> Array Size : 6641912320 (6334.22 GiB 6801.32 GB)
> Raid Devices : 12
> Total Devices : 12
> Preferred Minor : 2
>
> Update Time : Tue Mar 13 21:46:30 2012
> State : clean
> Active Devices : 12
> Working Devices : 12
> Failed Devices : 0
> Spare Devices : 0
> Checksum : bda9c758 - correct
> Events : 1647037
>
> Layout : left-symmetric
> Chunk Size : 128K
>
> Number Major Minor RaidDevice State
> this 0 65 18 0 active sync /dev/sdr2
>
> 0 0 65 18 0 active sync /dev/sdr2
> 1 1 8 226 1 active sync /dev/sdo2
> 2 2 8 242 2 active sync /dev/sdp2
> 3 3 65 2 3 active sync /dev/sdq2
> 4 4 65 145 4 active sync /dev/sdz1
> 5 5 8 178 5 active sync /dev/sdl2
> 6 6 8 162 6 active sync /dev/sdk2
> 7 7 8 210 7 active sync /dev/sdn2
> 8 8 8 194 8 active sync /dev/sdm2
> 9 9 65 113 9 active sync /dev/sdx1
> 10 10 65 129 10 active sync /dev/sdy1
> 11 11 65 97 11 active sync /dev/sdw1
> /dev/sdo2:
> Magic : a92b4efc
> Version : 0.90.00
> UUID : 08b30a7c:151f719c:e2349310:51678405
> Creation Time : Fri May 7 21:44:25 2010
> Raid Level : raid6
> Used Dev Size : 664191232 (633.42 GiB 680.13 GB)
> Array Size : 6641912320 (6334.22 GiB 6801.32 GB)
> Raid Devices : 12
> Total Devices : 12
> Preferred Minor : 2
>
> Update Time : Tue Mar 13 21:46:30 2012
> State : clean
> Active Devices : 12
> Working Devices : 12
> Failed Devices : 0
> Spare Devices : 0
> Checksum : bda9c7bb - correct
> Events : 1647037
>
> Layout : left-symmetric
> Chunk Size : 128K
>
> Number Major Minor RaidDevice State
> this 6 8 162 6 active sync /dev/sdk2
>
> 0 0 65 18 0 active sync /dev/sdr2
> 1 1 8 226 1 active sync /dev/sdo2
> 2 2 8 242 2 active sync /dev/sdp2
> 3 3 65 2 3 active sync /dev/sdq2
> 4 4 65 145 4 active sync /dev/sdz1
> 5 5 8 178 5 active sync /dev/sdl2
> 6 6 8 162 6 active sync /dev/sdk2
> 7 7 8 210 7 active sync /dev/sdn2
> 8 8 8 194 8 active sync /dev/sdm2
> 9 9 65 113 9 active sync /dev/sdx1
> 10 10 65 129 10 active sync /dev/sdy1
> 11 11 65 97 11 active sync /dev/sdw1
> /dev/sdp2:
> Magic : a92b4efc
> Version : 0.90.00
> UUID : 08b30a7c:151f719c:e2349310:51678405
> Creation Time : Fri May 7 21:44:25 2010
> Raid Level : raid6
> Used Dev Size : 664191232 (633.42 GiB 680.13 GB)
> Array Size : 6641912320 (6334.22 GiB 6801.32 GB)
> Raid Devices : 12
> Total Devices : 12
> Preferred Minor : 2
>
> Update Time : Tue Mar 13 21:46:30 2012
> State : clean
> Active Devices : 12
> Working Devices : 12
> Failed Devices : 0
> Spare Devices : 0
> Checksum : bda9c7c9 - correct
> Events : 1647037
>
> Layout : left-symmetric
> Chunk Size : 128K
>
> Number Major Minor RaidDevice State
> this 5 8 178 5 active sync /dev/sdl2
>
> 0 0 65 18 0 active sync /dev/sdr2
> 1 1 8 226 1 active sync /dev/sdo2
> 2 2 8 242 2 active sync /dev/sdp2
> 3 3 65 2 3 active sync /dev/sdq2
> 4 4 65 145 4 active sync /dev/sdz1
> 5 5 8 178 5 active sync /dev/sdl2
> 6 6 8 162 6 active sync /dev/sdk2
> 7 7 8 210 7 active sync /dev/sdn2
> 8 8 8 194 8 active sync /dev/sdm2
> 9 9 65 113 9 active sync /dev/sdx1
> 10 10 65 129 10 active sync /dev/sdy1
> 11 11 65 97 11 active sync /dev/sdw1
> /dev/sdq2:
> Magic : a92b4efc
> Version : 0.90.00
> UUID : 08b30a7c:151f719c:e2349310:51678405
> Creation Time : Fri May 7 21:44:25 2010
> Raid Level : raid6
> Used Dev Size : 664191232 (633.42 GiB 680.13 GB)
> Array Size : 6641912320 (6334.22 GiB 6801.32 GB)
> Raid Devices : 12
> Total Devices : 12
> Preferred Minor : 2
>
> Update Time : Tue Mar 13 21:46:30 2012
> State : clean
> Active Devices : 12
> Working Devices : 12
> Failed Devices : 0
> Spare Devices : 0
> Checksum : bda9c7df - correct
> Events : 1647037
>
> Layout : left-symmetric
> Chunk Size : 128K
>
> Number Major Minor RaidDevice State
> this 8 8 194 8 active sync /dev/sdm2
>
> 0 0 65 18 0 active sync /dev/sdr2
> 1 1 8 226 1 active sync /dev/sdo2
> 2 2 8 242 2 active sync /dev/sdp2
> 3 3 65 2 3 active sync /dev/sdq2
> 4 4 65 145 4 active sync /dev/sdz1
> 5 5 8 178 5 active sync /dev/sdl2
> 6 6 8 162 6 active sync /dev/sdk2
> 7 7 8 210 7 active sync /dev/sdn2
> 8 8 8 194 8 active sync /dev/sdm2
> 9 9 65 113 9 active sync /dev/sdx1
> 10 10 65 129 10 active sync /dev/sdy1
> 11 11 65 97 11 active sync /dev/sdw1
> /dev/sdr2:
> Magic : a92b4efc
> Version : 0.90.00
> UUID : 08b30a7c:151f719c:e2349310:51678405
> Creation Time : Fri May 7 21:44:25 2010
> Raid Level : raid6
> Used Dev Size : 664191232 (633.42 GiB 680.13 GB)
> Array Size : 6641912320 (6334.22 GiB 6801.32 GB)
> Raid Devices : 12
> Total Devices : 12
> Preferred Minor : 2
>
> Update Time : Tue Mar 13 21:46:30 2012
> State : clean
> Active Devices : 12
> Working Devices : 12
> Failed Devices : 0
> Spare Devices : 0
> Checksum : bda9c7ed - correct
> Events : 1647037
>
> Layout : left-symmetric
> Chunk Size : 128K
>
> Number Major Minor RaidDevice State
> this 7 8 210 7 active sync /dev/sdn2
>
> 0 0 65 18 0 active sync /dev/sdr2
> 1 1 8 226 1 active sync /dev/sdo2
> 2 2 8 242 2 active sync /dev/sdp2
> 3 3 65 2 3 active sync /dev/sdq2
> 4 4 65 145 4 active sync /dev/sdz1
> 5 5 8 178 5 active sync /dev/sdl2
> 6 6 8 162 6 active sync /dev/sdk2
> 7 7 8 210 7 active sync /dev/sdn2
> 8 8 8 194 8 active sync /dev/sdm2
> 9 9 65 113 9 active sync /dev/sdx1
> 10 10 65 129 10 active sync /dev/sdy1
> 11 11 65 97 11 active sync /dev/sdw1
> --
> 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 --]
next prev parent reply other threads:[~2012-03-14 19:26 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-14 18:29 Recovering raid6 with 3 of 12 disks Larkin Lowrey
2012-03-14 19:26 ` NeilBrown [this message]
2012-03-14 20:42 ` Larkin Lowrey
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20120315062611.0ff6bcc0@notabene.brown \
--to=neilb@suse.de \
--cc=linux-raid@vger.kernel.org \
--cc=llowrey@nuclearwinter.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).