From: Waxhead <waxhead@online.no>
To: linux-btrfs@vger.kernel.org
Subject: Btrfs RAID space utilization and bitrot reconstruction
Date: Sun, 01 Jul 2012 13:50:39 +0200 [thread overview]
Message-ID: <4FF0398F.3030802@online.no> (raw)
As far as I understand btrfs stores all data in huge chunks that are
striped, mirrored or "raid5/6'ed" throughout all the disks added to the
filesystem/volume.
How does btrfs deal with different sized disks? let's say that you for
example have 10 different disks that are 100GB,200GB,300GB...1000GB and
you create a btrfs filesystem with all the disks. How will the raid5
implementation distribute chunks in such a setup. I assume the
stripe+stripe+parity are separate chunks that are placed on separate
disks but how does btrfs select the best disk to store a chunk on? In
short will a slow disk slow down the entire "array", parts of it or will
btrfs attempt to use the fastest disks first?
Also since btrfs checksums both data and metadata I am thinking that at
least the raid6 implementation perhaps can (try to) reconstruct corrupt
data (and try to rewrite it) before reading an alternate copy. Can
someone please fill me in on the details here?
Finaly how does btrfs deals with advanced format (4k sectors) drives
when the entire drive (and not a partition) is used to build a btrfs
filesystem. Is proper alignment achieved?
next reply other threads:[~2012-07-01 12:10 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-01 11:50 Waxhead [this message]
2012-07-01 12:27 ` Btrfs RAID space utilization and bitrot reconstruction Hugo Mills
2012-07-02 18:00 ` Martin Steigerwald
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