On Tue, Jul 24, 2012 at 08:39:36PM -0400, Marios Titas wrote:

When I create a btrfs volume of size strictly less than 256 MiB then if I do
    mount /dev/sdb1 /mnt/test
the kernel tries unsuccessfully to do the mount with many other file systems
before successfully trying with btrfs. For volumes of size larger than
or equal to
256 MiB it just mounts the volume without doing that. Why is this discrepancy?

   Are you using the --mixed option when creating the filesystem? If
not, you should do with something that small.

   Hugo.

Another possibly related symptom is that the volume does not appear in
/dev/disk/by-label and /dev/disk/by-uuid at all. This means that it is
impossible
to mount the volume by uuid or label.

To make sure that this isn't a udev bug, I booted my system with init=/bin/bash
in the kernel command line, and then I tried again to mount the
volume. This time
it would not mount it at all unless I explicitly specified the fs
type. On the other
hand, it could mount larger volumes without any issues.

All the experiments were done in an initially zeroed out disk. I am
using 3.4.6 kernel
with btrfs from 3.5 and the latest btrfs-progs from git.

-- 
=== Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
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