From: Ilya Dryomov <idryomov@gmail.com>
To: Phillip Susi <psusi@cfl.rr.com>
Cc: linux-btrfs@vger.kernel.org
Subject: Re: [PATCH 00/21] [RFC] Btrfs: restriper
Date: Tue, 15 Nov 2011 17:06:55 +0200 [thread overview]
Message-ID: <20111115150655.GA24302@zambezi.lan> (raw)
In-Reply-To: <4EC2782A.3050005@cfl.rr.com>
On Tue, Nov 15, 2011 at 09:33:14AM -0500, Phillip Susi wrote:
> On 11/15/2011 4:22 AM, Ilya Dryomov wrote:
> >Restriper won't let you do raid1 -> dup transition because dup is only
> >allowed for a single-spindle FS, so you'll end up with error "btrfs:
> >unable to start restripe ...".
> >
> >There is no way to prioritize disks during restripe. To get dup back
> >you'll have to convert everything to single, remove the second drive and
> >then convert metadata from single to dup.
>
> So there is no way to put a disk into read only mode and prevent
> allocations of new chunks there?
>
> It seems like both of these limitations are highly undesirable when
> trying to recover from a failing disk. You don't want any more data
> being written to the failing disk while you are trying to remove it,
> and you certainly don't want to drop back to a single copy of data
> that is then written to the failing disk.
If you have a failing disk in a raid setup, you don't need to downgrade
your raid, you can add a third drive and remove the failing one. But
that's inconvenient and most of the time you'll have to do a full
balance.
So another thing I'm working on is drive swap, when it's done it will
take care of the failing disk scenario. If you have a raid setup and
one of the disks gone bad you'll be able to say
btrfs device replace FAILED NEW <mountpoint>
and it will put valid copy onto the fresh drive, basically doing a raid
rebuild.
Thanks,
Ilya
next prev parent reply other threads:[~2011-11-15 15:06 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-23 20:01 [PATCH 00/21] [RFC] Btrfs: restriper Ilya Dryomov
2011-08-23 20:01 ` [PATCH 01/21] Btrfs: get rid of *_alloc_profile fields Ilya Dryomov
2011-09-27 12:51 ` David Sterba
2011-08-23 20:01 ` [PATCH 02/21] Btrfs: introduce masks for chunk type and profile Ilya Dryomov
2011-08-23 20:01 ` [PATCH 03/21] Btrfs: add BTRFS_AVAIL_ALLOC_BIT_SINGLE bit Ilya Dryomov
2011-11-01 7:56 ` Arne Jansen
2011-08-23 20:01 ` [PATCH 04/21] Btrfs: make avail_*_alloc_bits fields dynamic Ilya Dryomov
2011-08-23 20:01 ` [PATCH 05/21] Btrfs: add basic restriper infrastructure Ilya Dryomov
2011-11-01 10:08 ` Arne Jansen
2011-11-01 11:07 ` David Sterba
2011-11-01 11:08 ` Arne Jansen
2011-08-23 20:01 ` [PATCH 06/21] Btrfs: implement online profile changing Ilya Dryomov
2011-08-23 20:01 ` [PATCH 07/21] Btrfs: add basic infrastructure for selective balancing Ilya Dryomov
2011-09-27 13:02 ` David Sterba
2011-09-27 17:28 ` Ilya Dryomov
2011-08-23 20:01 ` [PATCH 08/21] Btrfs: soft profile changing mode (aka soft convert) Ilya Dryomov
2011-08-23 20:01 ` [PATCH 09/21] Btrfs: profiles filter Ilya Dryomov
2011-08-23 20:01 ` [PATCH 10/21] Btrfs: usage filter Ilya Dryomov
2011-09-27 13:22 ` David Sterba
2011-11-01 10:18 ` Arne Jansen
2011-08-23 20:01 ` [PATCH 11/21] Btrfs: devid filter Ilya Dryomov
2011-08-23 20:01 ` [PATCH 12/21] Btrfs: devid subset filter Ilya Dryomov
2011-08-23 20:01 ` [PATCH 13/21] Btrfs: virtual address space " Ilya Dryomov
2011-08-23 20:01 ` [PATCH 14/21] Btrfs: save restripe parameters to disk Ilya Dryomov
2011-09-27 13:43 ` David Sterba
2011-11-01 10:29 ` Arne Jansen
2011-08-23 20:01 ` [PATCH 15/21] Btrfs: recover restripe on mount Ilya Dryomov
2011-11-01 10:57 ` Arne Jansen
2011-08-23 20:01 ` [PATCH 16/21] Btrfs: allow for cancelling restriper Ilya Dryomov
2011-08-23 20:01 ` [PATCH 17/21] Btrfs: allow for pausing restriper Ilya Dryomov
2011-11-01 11:46 ` Arne Jansen
2011-08-23 20:01 ` [PATCH 18/21] Btrfs: allow for resuming restriper after it was paused Ilya Dryomov
2011-08-23 20:02 ` [PATCH 19/21] Btrfs: add skip_restripe mount option Ilya Dryomov
2011-08-23 20:02 ` [PATCH 20/21] Btrfs: get rid of btrfs_balance() function Ilya Dryomov
2011-08-23 20:02 ` [PATCH 21/21] Btrfs: add restripe progress reporting Ilya Dryomov
2011-09-27 12:47 ` [PATCH 00/21] [RFC] Btrfs: restriper David Sterba
2011-11-14 23:59 ` Phillip Susi
2011-11-15 9:22 ` Ilya Dryomov
2011-11-15 14:33 ` Phillip Susi
2011-11-15 15:06 ` Ilya Dryomov [this message]
2011-11-17 3:13 ` Phillip Susi
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