From: jim owens <jowens@hp.com>
To: RK <rkasl@computer.org>
Cc: linux-btrfs <linux-btrfs@vger.kernel.org>
Subject: Re: RAID-10 arrays built with btrfs & md report 2x difference in available size?
Date: Fri, 29 Jan 2010 18:46:38 -0500 [thread overview]
Message-ID: <4B63735E.1060609@hp.com> (raw)
In-Reply-To: <4B63634F.6090600@computer.org>
RK wrote:
> I think so too -- I have six 1TB drives on RAID-10 btrfs and it shows
> that I have 5.5TB free space .. how that can be ?
>
> # df -h
> Filesystem Size Used Avail Use% Mounted on
> /dev/sde1 66G 3.8G 59G 7% /
> /dev/sda 5.5T 28K 5.5T 1% /mnt/btrfs
As has been discussed multiple times on the list, btrfs reports
RAW storage so 6 x 1TB is 6 TB. And the use rate will be double
for each block written (i.e. 2 blocks used) for raid10 (or raid1).
And yes, it is "not what you expect", but it is the only method
that can remain accurate under the mixed raid modes possible
on a per-file-basis in btrfs.
jim
next prev parent reply other threads:[~2010-01-29 23:46 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-29 21:57 RAID-10 arrays built with btrfs & md report 2x difference in available size? Thomas Kupper
2010-01-29 22:13 ` 0bo0
2010-01-29 22:38 ` RK
2010-01-29 23:46 ` jim owens [this message]
2010-01-29 23:53 ` 0bo0
2010-01-30 13:24 ` Goffredo Baroncelli
2010-01-30 13:29 ` Goffredo Baroncelli
2010-01-30 15:36 ` jim owens
2010-02-08 3:52 ` 0bo0
2010-02-08 3:54 ` 0bo0
2010-02-08 14:33 ` jim owens
-- strict thread matches above, loose matches on Subject: below --
2010-01-24 5:31 0bo0
2010-01-24 12:01 ` RK
2010-01-24 17:18 ` 0bo0
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