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From: Chris Murphy <>
To: Btrfs BTRFS <>
Subject: Re: mount hangs after disk crash (RAID-1)
Date: Thu, 22 May 2014 10:27:28 -0600	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <pan$4965$e2755b8c$eb8c082f$>

On May 22, 2014, at 3:43 AM, Duncan <> wrote:
> Note that unlike md/raid1, btrfs raid1 won't mount writable with only a 
> single device.  You must have at least two devices to mount writable, tho 
> a formerly two-device raid1 with a device missing should mount read-only.

No, a single device from a two device Btrfs raid1 is normally mountable degraded,rw. I did this just a week ago when bug "kernel BUG at fs/btrfs/locking.c when mounting with previously missing device". At one point when reproducing it, I was running degraded,rw with a single device for several hours without problems.

Try -o recovery,degraded

I would drop the other options for now, since they aren't necessary to recover from a device failure.

Chris Murphy

      reply	other threads:[~2014-05-22 16:27 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-05-22  2:22 mount hangs after disk crash (RAID-1) Tomasz Chmielewski
2014-05-22  8:51 ` Tomasz Chmielewski
2014-05-22 15:16   ` Tomasz Chmielewski
2014-05-22 17:50     ` Tomasz Chmielewski
2014-05-22 18:20       ` Chris Murphy
2014-05-22 21:06       ` Duncan
2014-05-22 22:07       ` Chris Murphy
2014-05-22  9:43 ` Duncan
2014-05-22 16:27   ` Chris Murphy [this message]

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