From: Dave Chinner <david@fromorbit.com>
To: Chris Murphy <lists@colorremedies.com>
Cc: xfs list <linux-xfs@vger.kernel.org>
Subject: Re: LVM thinp, mkfs "device is not properly aligned"
Date: Thu, 16 Nov 2017 11:07:03 +1100 [thread overview]
Message-ID: <20171116000703.GG4094@dastard> (raw)
In-Reply-To: <CAJCQCtR1eLc3n-19po0z8eF3tcmj6rxuPK6fcJft=swuCGSVwA@mail.gmail.com>
On Wed, Nov 15, 2017 at 04:20:59PM -0700, Chris Murphy wrote:
> # mkfs.xfs /dev/mapper/vg-timemachine
> warning: device is not properly aligned /dev/mapper/vg-timemachine
> Use -f to force usage of a misaligned device
That is emitted when blikid tells XFS that the device it is about to
format is not correctly aligned.
The check that is failing:
if (blkid_topology_get_alignment_offset(tp) != 0)
>From here:
https://www.kernel.org/pub/linux/utils/util-linux/v2.21/libblkid-docs/libblkid-Topology-information.html
ALIGNMENT_OFFSET: indicates how many bytes the beginning of the
device is offset from the disk's natural alignment.
....
> $ lsblk -t
>
(Trimmed for brevity and readability)
.....
> NAME ALIGNMENT MIN-IO OPT-IO
> sda 0 4096 0
> sda1 0 4096 0
> sda2 0 4096 0
> brick1 512 4096 0
> sda3 0 4096 0
> sda4 0 4096 0
> sda5 0 4096 0
> vg-cryptoswap 512 4096 0
> swap 512 4096 0
> vg-thintastic_tmeta 512 4096 0
> vg-thintastic-tpool 512 524288 524288
> vg-thintastic 512 524288 524288
> vg-timemachine 512 524288 524288
> vg-thintastic_tdata 512 4096 0
> vg-thintastic-tpool 512 524288 524288
> vg-thintastic 512 524288 524288
> vg-timemachine 512 524288 524288
>
What you can see here is that all the volume groups have a non-zero
alignment - they are all off by one sector - and that's what
mkfs.xfs is warning you about. i.e. something's not quite right at
the LVM layer....
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
next prev parent reply other threads:[~2017-11-16 0:15 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-15 23:20 LVM thinp, mkfs "device is not properly aligned" Chris Murphy
2017-11-16 0:07 ` Dave Chinner [this message]
2017-11-16 2:19 ` Chris Murphy
2017-11-16 2:29 ` Chris Murphy
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