From: Roman Mamedov <rm@romanrm.net>
To: Remi Gauvin <remi@georgianit.com>
Cc: "linux-btrfs@vger.kernel.org" <linux-btrfs@vger.kernel.org>
Subject: Re: Balance on 5-disk RAID1 put all data on 2 disks, leaving the rest empty
Date: Thu, 26 Oct 2023 02:15:51 +0500 [thread overview]
Message-ID: <20231026021551.55802873@nvm> (raw)
In-Reply-To: <16acffd1-9704-9681-c2d4-4f5b8280ade0@georgianit.com>
On Wed, 25 Oct 2023 17:08:08 -0400
Remi Gauvin <remi@georgianit.com> wrote:
> On 2023-10-25 4:29 p.m., Peter Wedder wrote:
> > Hello,
> >
> > I had a RAID1 array on top of 4x4TB drives. Recently I removed one 4TB drive and added two 16TB drives to it. After running a full, unfiltered balance on the array, I am left in a situation where all the 4TB drives are completely empty, and all the data and metadata is on the 16TB drives. Is this normal? I was expecting to have at least some data on the smaller drives.
> >
>
> Yes, this is normal. The BTRFS allocates space in drives with the the
> most available free space. The idea is to balance the 'unallocated'
> space on each drive, so they can be filled evenly. The 4TB drives will
> be used when the 16TB dives have less than 4TB unallocated.
Interesting question and resolution. I'd be surprised by that as well.
Now, a great chance to "btrfs dev delete" all three remaining 4TB drives and
unplug them for the time being, to save on noise, heat and power consumption!
--
With respect,
Roman
next prev parent reply other threads:[~2023-10-25 21:16 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-25 20:29 Balance on 5-disk RAID1 put all data on 2 disks, leaving the rest empty Peter Wedder
2023-10-25 21:08 ` Remi Gauvin
2023-10-25 21:15 ` Roman Mamedov [this message]
2023-10-27 4:21 ` Anand Jain
2023-11-01 19:20 ` Pedro Macedo
2023-11-02 2:13 ` Zygo Blaxell
2023-11-02 5:11 ` Paul Jones
2023-11-02 13:50 ` Zygo Blaxell
2023-11-02 23:57 ` waxhead
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