From: Marc MERLIN <marc@merlins.org>
To: linux-btrfs@vger.kernel.org
Subject: Is metadata redundant over more than one drive with raid0 too?
Date: Sat, 3 May 2014 16:27:02 -0700 [thread overview]
Message-ID: <20140503232702.GC9061@merlins.org> (raw)
So, I was thinking. In the past, I've done this:
mkfs.btrfs -d raid0 -m raid1 -L btrfs_raid0 /dev/mapper/raid0d*
My rationale at the time was that if I lose a drive, I'll still have
full metadata for the entire filesystem and only missing files.
If I have raid1 with 2 drives, I should end up with 4 copies of each
file's metadata, right?
But now I have 2 questions
1) btrfs has two copies of all metadata on even a single drive, correct?
If so, and I have a -d raid0 -m raid0 filesystem, are both copies of the
metadata on the same drive or is btrfs smart enough to spread out
metadata copies so that they're not on the same drive?
2) does btrfs lay out files on raid0 so that files aren't striped across
more than one drive, so that if I lose a drive, I only lose whole files,
but not little chunks of all my files, making my entire FS toast?
Thanks,
Marc
--
"A mouse is a device used to point at the xterm you want to type in" - A.S.R.
Microsoft is to operating systems ....
.... what McDonalds is to gourmet cooking
Home page: http://marc.merlins.org/ | PGP 1024R/763BE901
next reply other threads:[~2014-05-04 5:46 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-03 23:27 Marc MERLIN [this message]
2014-05-04 6:57 ` Is metadata redundant over more than one drive with raid0 too? Brendan Hide
2014-05-04 7:24 ` Marc MERLIN
2014-05-04 7:44 ` Brendan Hide
2014-05-05 1:27 ` Marc MERLIN
2014-05-06 19:05 ` Duncan
2014-05-06 19:39 ` Duncan
2014-05-05 0:46 ` Daniel Lee
2014-05-05 5:06 ` Marc MERLIN
2014-05-06 17:16 ` Duncan
2014-05-07 8:18 ` raid0 vs single, and should we allow -mdup by default on SSDs? Marc MERLIN
2014-05-07 8:29 ` Hugo Mills
2014-05-07 8:52 ` Marc MERLIN
2014-05-07 22:39 ` Mitch Harder
2014-05-04 21:49 ` Is metadata redundant over more than one drive with raid0 too? Duncan
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