From: Duncan <1i5t5.duncan@cox.net>
To: linux-btrfs@vger.kernel.org
Subject: Re: [PATCH 00/13 v3] Introduce device state 'failed', Hot spare and Auto replace
Date: Mon, 4 Apr 2016 06:09:41 +0000 (UTC) [thread overview]
Message-ID: <pan$64d8b$718e385e$1ef143f5$1db0a45a@cox.net> (raw)
In-Reply-To: pan$5fc01$c48cb58$b5aadf3d$c2af2f78@cox.net
Duncan posted on Mon, 04 Apr 2016 04:45:16 +0000 as excerpted:
> Kai Krakow posted on Mon, 04 Apr 2016 02:00:43 +0200 as excerpted:
>
>> Does this also implement "copy-back" - thus, it returns the hot-spare
>> device to global hot-spares when the failed device has been replaced?
>
> I don't believe it does that in this initial implementation, anyway.
>
> There's a number of issues with the initial implementation, including
> the fact that the hot-spare is global only and can't be specifically
> assigned to a filesystem or set of filesystems, which means, if you have
> multiple filesystems using different sized devices, the hot-spares must
> be sized to match the largest device they could replace,
Obviously the sizes issue is problematic for the hot-spare-return
situation as well, since it would then be possible for an appropriately
large replacement device to replace a much smaller device on some
filesystem, which would then put the much smaller device into rotation as
a hot-spare where it could end up picked to replace a far larger device.
As there's currently no intelligence as to device sizes, etc, it just
picks the next device in the hot-spares list and tries to use it, oops!
So hot-spare-return really will need to wait until per-filesystem hot-
spares and/or some sizing intelligence is added.
--
Duncan - List replies preferred. No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master." Richard Stallman
next prev parent reply other threads:[~2016-04-04 6:09 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-02 1:30 [PATCH 00/13 v3] Introduce device state 'failed', Hot spare and Auto replace Anand Jain
2016-04-02 1:30 ` [PATCH 01/13] btrfs: Introduce a new function to check if all chunks a OK for degraded mount Anand Jain
2016-04-02 1:30 ` [PATCH 02/13] btrfs: Do per-chunk check for mount time check Anand Jain
2016-04-02 1:30 ` [PATCH 03/13] btrfs: Do per-chunk degraded check for remount Anand Jain
2016-04-02 1:30 ` [PATCH 04/13] btrfs: Allow barrier_all_devices to do per-chunk device check Anand Jain
2016-04-02 1:30 ` [PATCH 05/13] btrfs: Cleanup num_tolerated_disk_barrier_failures Anand Jain
2016-04-02 1:30 ` [PATCH 06/13] btrfs: introduce BTRFS_FEATURE_INCOMPAT_SPARE_DEV Anand Jain
2016-04-02 1:30 ` [PATCH 07/13] btrfs: add check not to mount a spare device Anand Jain
2016-04-02 1:30 ` [PATCH 08/13] btrfs: support btrfs dev scan for " Anand Jain
2016-04-02 1:30 ` [PATCH 09/13] btrfs: provide framework to get and put a " Anand Jain
2016-04-02 1:30 ` [PATCH 10/13] btrfs: introduce helper functions to perform hot replace Anand Jain
2016-04-02 5:40 ` kbuild test robot
2016-04-07 20:00 ` Yauhen Kharuzhy
2016-04-08 3:58 ` Anand Jain
2016-04-08 22:05 ` Yauhen Kharuzhy
2016-04-12 14:16 ` Anand Jain
2016-04-02 1:30 ` [PATCH 11/13] btrfs: introduce device dynamic state transition to offline or failed Anand Jain
2016-04-02 1:30 ` [PATCH 12/13] btrfs: check device for critical errors and mark failed Anand Jain
2016-04-02 1:30 ` [PATCH 13/13] btrfs: check for failed device and hot replace Anand Jain
2016-04-04 0:00 ` [PATCH 00/13 v3] Introduce device state 'failed', Hot spare and Auto replace Kai Krakow
2016-04-04 4:45 ` Duncan
2016-04-04 6:09 ` Duncan [this message]
2016-04-04 20:15 ` Kai Krakow
2016-04-05 3:02 ` Duncan
2016-04-04 6:19 ` Anand Jain
2016-04-04 20:07 ` Kai Krakow
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