From: "Matthew Tice" <mjtice@gmail.com>
To: linux-raid@vger.kernel.org
Subject: RE: Removed two drives (still valid and working) from raid-5 and need to add them back in.
Date: Mon, 14 Mar 2011 06:29:50 -0600 [thread overview]
Message-ID: <000301cbe243$846419b0$8d2c4d10$@com> (raw)
In-Reply-To: <5EB70557-47EB-4F81-A158-4A5157EB7E37@gmail.com>
On Mar 12, 2011, at 8:56 PM, Phil Turmel wrote:
> On 03/12/2011 10:38 PM, mtice wrote:
>> Hi Phil, thanks for the reply.
>> Here is the output of mdadm -E /dev/sd[cdef]
>>
>> /dev/sdc:
>> Magic : a92b4efc
>> Version : 00.90.00
>> UUID : 11c1cdd8:60ec9a90:2e29483d:f114274d (local to host
storage)
>> Creation Time : Thu May 27 15:35:56 2010
>> Raid Level : raid5
>> Used Dev Size : 732574464 (698.64 GiB 750.16 GB)
>> Array Size : 2197723392 (2095.91 GiB 2250.47 GB)
>> Raid Devices : 4
>> Total Devices : 5
>> Preferred Minor : 0
>>
>> Update Time : Fri Mar 11 15:53:35 2011
>> State : clean
>> Active Devices : 2
>> Working Devices : 4
>> Failed Devices : 2
>> Spare Devices : 2
>> Checksum : 3d3b86 - correct
>> Events : 43200
>>
>> Layout : left-symmetric
>> Chunk Size : 64K
>>
>> Number Major Minor RaidDevice State
>> this 3 8 32 3 active sync /dev/sdc
>>
>> 0 0 8 80 0 active sync /dev/sdf
>> 1 1 0 0 1 faulty removed
>> 2 2 0 0 2 faulty removed
>> 3 3 8 32 3 active sync /dev/sdc
>> 4 4 8 64 4 spare /dev/sde
>> 5 5 8 112 5 spare
>> /dev/sdd:
>> Magic : a92b4efc
>> Version : 00.90.00
>> UUID : 11c1cdd8:60ec9a90:2e29483d:f114274d (local to host
storage)
>> Creation Time : Thu May 27 15:35:56 2010
>> Raid Level : raid5
>> Used Dev Size : 732574464 (698.64 GiB 750.16 GB)
>> Array Size : 2197723392 (2095.91 GiB 2250.47 GB)
>> Raid Devices : 4
>> Total Devices : 5
>> Preferred Minor : 0
>>
>> Update Time : Fri Mar 11 15:53:35 2011
>> State : clean
>> Active Devices : 2
>> Working Devices : 4
>> Failed Devices : 2
>> Spare Devices : 2
>> Checksum : 3d3bd4 - correct
>> Events : 43200
>>
>> Layout : left-symmetric
>> Chunk Size : 64K
>>
>> Number Major Minor RaidDevice State
>> this 5 8 112 5 spare
>>
>> 0 0 8 80 0 active sync /dev/sdf
>> 1 1 0 0 1 faulty removed
>> 2 2 0 0 2 faulty removed
>> 3 3 8 32 3 active sync /dev/sdc
>> 4 4 8 64 4 spare /dev/sde
>> 5 5 8 112 5 spare
>> /dev/sde:
>> Magic : a92b4efc
>> Version : 00.90.00
>> UUID : 11c1cdd8:60ec9a90:2e29483d:f114274d (local to host
storage)
>> Creation Time : Thu May 27 15:35:56 2010
>> Raid Level : raid5
>> Used Dev Size : 732574464 (698.64 GiB 750.16 GB)
>> Array Size : 2197723392 (2095.91 GiB 2250.47 GB)
>> Raid Devices : 4
>> Total Devices : 5
>> Preferred Minor : 0
>>
>> Update Time : Fri Mar 11 15:53:35 2011
>> State : clean
>> Active Devices : 2
>> Working Devices : 4
>> Failed Devices : 2
>> Spare Devices : 2
>> Checksum : 3d3ba2 - correct
>> Events : 43200
>>
>> Layout : left-symmetric
>> Chunk Size : 64K
>>
>> Number Major Minor RaidDevice State
>> this 4 8 64 4 spare /dev/sde
>>
>> 0 0 8 80 0 active sync /dev/sdf
>> 1 1 0 0 1 faulty removed
>> 2 2 0 0 2 faulty removed
>> 3 3 8 32 3 active sync /dev/sdc
>> 4 4 8 64 4 spare /dev/sde
>> 5 5 8 112 5 spare
>> /dev/sdf:
>> Magic : a92b4efc
>> Version : 00.90.00
>> UUID : 11c1cdd8:60ec9a90:2e29483d:f114274d (local to host
storage)
>> Creation Time : Thu May 27 15:35:56 2010
>> Raid Level : raid5
>> Used Dev Size : 732574464 (698.64 GiB 750.16 GB)
>> Array Size : 2197723392 (2095.91 GiB 2250.47 GB)
>> Raid Devices : 4
>> Total Devices : 5
>> Preferred Minor : 0
>>
>> Update Time : Fri Mar 11 15:53:35 2011
>> State : clean
>> Active Devices : 2
>> Working Devices : 4
>> Failed Devices : 2
>> Spare Devices : 2
>> Checksum : 3d3bb0 - correct
>> Events : 43200
>>
>> Layout : left-symmetric
>> Chunk Size : 64K
>>
>> Number Major Minor RaidDevice State
>> this 0 8 80 0 active sync /dev/sdf
>>
>> 0 0 8 80 0 active sync /dev/sdf
>> 1 1 0 0 1 faulty removed
>> 2 2 0 0 2 faulty removed
>> 3 3 8 32 3 active sync /dev/sdc
>> 4 4 8 64 4 spare /dev/sde
>> 5 5 8 112 5 spare
>>
>>
>> I ran mdadm --assemble --force /dev/md0 but it erred with:
>>
>> mdadm: device /dev/md0 already active - cannot assemble it
>
> You would have to stop the array first. But it won't matter. The dropped
devices don't remember their role. But you have a 50-50 chance of getting
it right. It's either:
>
> mdadm --create /dev/md0 --level=5 --raid-devices=4 --assume-clean
--metadata=0.90 --chunk=64k /dev/sdf /dev/sde /dev/sdd /dev/sdc
>
> or with /dev/sde and /dev/sdd swapped.
>
> I suggest you try it both ways, with an "fsck -n" to see which has a
consistent filesystem. Once you figure out which order is correct, do a
real fsck to fix up any minor errors from the inadvertent unplug, then mount
and grab a fresh backup.
>
> Let us know how it turns out (I'm about to sign off for the night...).
>
> Phil
That did it. Thanks, Phil!
I was able to get the drives added back in with:
mdadm --create /dev/md0 --level=5 --raid-devices=4 --assume-clean
--metadata=0.90 --chunk=64 /dev/sdf /dev/sde /dev/sdd /dev/sdc
An fsck -n came back clean so I ran another fsck and mounted it up and all
looks good.
Thanks for your help!
Matt
prev parent reply other threads:[~2011-03-14 12:29 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-12 19:12 Removed two drives (still valid and working) from raid-5 and need to add them back in mtice
2011-03-13 1:01 ` mtice
2011-03-13 3:26 ` Phil Turmel
2011-03-13 3:38 ` mtice
[not found] ` <4D7C4083.2010000@turmel.org>
2011-03-14 0:14 ` mtice
2011-03-14 12:29 ` Matthew Tice [this message]
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