From: Roman Mamedov <rm@romanrm.net>
To: Liu Bo <bo.li.liu@oracle.com>
Cc: linux-btrfs@vger.kernel.org
Subject: Re: [PATCH 00/14 RFC] Btrfs: Add journal for raid5/6 writes
Date: Tue, 1 Aug 2017 22:25:47 +0500 [thread overview]
Message-ID: <20170801222547.35d1bd03@natsu> (raw)
In-Reply-To: <20170801161439.13426-1-bo.li.liu@oracle.com>
On Tue, 1 Aug 2017 10:14:23 -0600
Liu Bo <bo.li.liu@oracle.com> wrote:
> This aims to fix write hole issue on btrfs raid5/6 setup by adding a
> separate disk as a journal (aka raid5/6 log), so that after unclean
> shutdown we can make sure data and parity are consistent on the raid
> array by replaying the journal.
Could it be possible to designate areas on the in-array devices to be used as
journal?
While md doesn't have much spare room in its metadata for extraneous things
like this, Btrfs could use almost as much as it wants to, adding to size of the
FS metadata areas. Reliability-wise, the log could be stored as RAID1 chunks.
It doesn't seem convenient to need having an additional storage device around
just for the log, and also needing to maintain its fault tolerance yourself (so
the log device would better be on a mirror, such as mdadm RAID1? more expense
and maintenance complexity).
--
With respect,
Roman
next prev parent reply other threads:[~2017-08-01 17:25 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-01 16:14 [PATCH 00/14 RFC] Btrfs: Add journal for raid5/6 writes Liu Bo
2017-08-01 16:14 ` [PATCH 01/14] Btrfs: raid56: add raid56 log via add_dev v2 ioctl Liu Bo
2017-08-02 19:25 ` Nikolay Borisov
2017-08-01 16:14 ` [PATCH 02/14] Btrfs: raid56: do not allocate chunk on raid56 log Liu Bo
2017-08-01 16:14 ` [PATCH 03/14] Btrfs: raid56: detect raid56 log on mount Liu Bo
2017-08-01 16:14 ` [PATCH 04/14] Btrfs: raid56: add verbose debug Liu Bo
2017-08-01 16:14 ` [PATCH 05/14] Btrfs: raid56: add stripe log for raid5/6 Liu Bo
2017-08-01 16:14 ` [PATCH 06/14] Btrfs: raid56: add reclaim support Liu Bo
2017-08-01 16:14 ` [PATCH 07/14] Btrfs: raid56: load r5log Liu Bo
2017-08-01 16:14 ` [PATCH 08/14] Btrfs: raid56: log recovery Liu Bo
2017-08-01 16:14 ` [PATCH 09/14] Btrfs: raid56: add readahead for recovery Liu Bo
2017-08-01 16:14 ` [PATCH 10/14] Btrfs: raid56: use the readahead helper to get page Liu Bo
2017-08-01 16:14 ` [PATCH 11/14] Btrfs: raid56: add csum support Liu Bo
2017-08-01 16:14 ` [PATCH 12/14] Btrfs: raid56: fix error handling while adding a log device Liu Bo
2017-08-01 16:14 ` [PATCH 13/14] Btrfs: raid56: initialize raid5/6 log after adding it Liu Bo
2017-08-01 16:14 ` [PATCH 14/14] Btrfs: raid56: maintain IO order on raid5/6 log Liu Bo
2017-08-01 16:14 ` [PATCH 1/2] Btrfs-progs: add option to add raid5/6 log device Liu Bo
2017-08-01 16:14 ` [PATCH 2/2] Btrfs-progs: introduce super_journal_tail to inspect-dump-super Liu Bo
2017-08-01 17:25 ` Roman Mamedov [this message]
2017-08-01 17:03 ` [PATCH 00/14 RFC] Btrfs: Add journal for raid5/6 writes Liu Bo
2017-08-01 17:39 ` Austin S. Hemmelgarn
2017-08-01 17:07 ` Liu Bo
2017-08-02 18:47 ` Chris Mason
2018-05-03 19:16 ` Goffredo Baroncelli
2017-08-01 17:28 ` Hugo Mills
2017-08-01 16:56 ` Liu Bo
2017-08-01 18:15 ` Hugo Mills
2017-08-01 17:42 ` Goffredo Baroncelli
2017-08-01 17:24 ` Liu Bo
2017-08-01 22:14 ` Goffredo Baroncelli
2017-08-02 17:57 ` Liu Bo
2017-08-02 20:41 ` Goffredo Baroncelli
2017-08-02 20:27 ` Liu Bo
2017-08-03 4:02 ` Duncan
2017-08-03 4:40 ` Goffredo Baroncelli
2017-08-23 15:28 ` Chris Murphy
2017-08-23 15:47 ` Austin S. Hemmelgarn
2017-08-25 13:53 ` Goffredo Baroncelli
2017-08-01 21:00 ` Christoph Anton Mitterer
2017-08-01 22:24 ` Goffredo Baroncelli
[not found] <CAL5DHTFA8G5fq=BQ7N7qQimesjygKTiBR2qZF4YBRAsAjB_L5Q@mail.gmail.com>
2019-07-30 16:20 ` Goffredo Baroncelli
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