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From: Hubert Tonneau <hubert.tonneau@fullpliant.org>
To: linux-btrfs@vger.kernel.org
Subject: Avoiding BRTFS RAID5 write hole
Date: Tue, 12 Nov 2019 15:13:26 GMT	[thread overview]
Message-ID: <0JG8IAF11@briare1.fullpliant.org> (raw)

Hi,

In order to close the RAID5 write hole, I prepose the add a mount option that would change RAID5 (and RAID6) behaviour :

. When overwriting a RAID5 stripe, first convert it to RAID1 (convert it to RAID1C3 if it was RAID6)

. Have a background process that converts RAID1 stripes to RAID5 (RAID1C3 to RAID6)

Expected advantages are :
. the low level features set basically remains the same
. the filesystem format remains the same
. old kernels and btrs-progs would not be disturbed

The end result would be a mixed filesystem where active parts are RAID1 and archives one are RAID5.

Regards,
Hubert Tonneau

             reply	other threads:[~2019-11-12 14:28 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-12 15:13 Hubert Tonneau [this message]
2019-11-12 18:44 ` Avoiding BRTFS RAID5 write hole Chris Murphy
2019-11-12 19:49 ` Goffredo Baroncelli
2019-11-14  4:25   ` Zygo Blaxell
  -- strict thread matches above, loose matches on Subject: below --
2019-11-12 22:27 Hubert Tonneau
2019-11-13 19:34 ` Goffredo Baroncelli
2019-11-13 22:29 Hubert Tonneau
2019-11-13 22:51 ` waxhead
2019-11-14 21:25 ` Goffredo Baroncelli
2019-11-15 20:41   ` Hubert Tonneau
2019-11-17  8:53     ` Goffredo Baroncelli
2019-11-17 19:49       ` Hubert Tonneau
2019-11-28 11:37       ` Hubert Tonneau

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