From: Russell Coker <russell@coker.com.au>
To: linux-btrfs <linux-btrfs@vger.kernel.org>
Subject: staggered stripes
Date: Thu, 15 May 2014 19:00:10 +1000 [thread overview]
Message-ID: <2751140.Zb1qMBeNgk@xev> (raw)
http://www.cs.wisc.edu/adsl/Publications/corruption-fast08.html
Page 13 of the above paper says:
# Figure 12 presents for each block number, the number of disk drives of disk
# model ‘E-1’ that developed a checksum mismatch at that block number. We see
# in the figure that many disks develop corruption for a specific set of block
# numbers. We also verified that (i) other disk models did not develop
# multiple check-sum mismatches for the same set of block numbers (ii) the
# disks that developed mismatches at the same block numbers belong to
# different storage systems, and (iii) our software stack has no specific data
# structure that is placed at the block numbers of interest.
#
# These observations indicate that hardware or firmware bugs that affect
# specific sets of block numbers might exist. Therefore, RAID system designers
# may be well-advised to use staggered stripes such that the blocks that form
# a stripe (providing the required redundancy) are placed at different block
# numbers on different disks.
Does the BTRFS RAID functionality do such staggered stripes? If not could it
be added?
I guess there's nothing stopping a sysadmin from allocating an unused
partition at the start of each disk and use a different size for each disk.
But I think it would be best to do this inside the filesystem.
Also this is another reason for having DUP+RAID-1.
--
My Main Blog http://etbe.coker.com.au/
My Documents Blog http://doc.coker.com.au/
next reply other threads:[~2014-05-15 9:00 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-15 9:00 Russell Coker [this message]
2014-05-15 9:31 ` staggered stripes Duncan
2014-05-15 14:38 ` Russell Coker
2014-05-15 16:15 ` Brendan Hide
2014-05-15 16:18 ` Hugo Mills
[not found] ` <2Ee51o00g0uXw0U01Ee7j5>
2014-05-16 4:17 ` Duncan
2014-05-15 9:34 ` Hugo Mills
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