On Thu, Jul 26, 2012 at 03:09:59PM -0600, David Sterba wrote:

On Wed, Jul 25, 2012 at 03:26:20PM +0200, Cyril B.  wrote:

quoted

When creating a filesystem with devices of different sizes, the resulting 
filesystem total size depends on the device order specified to mkfs. When 
the smaller device is specified first, the second (larger) device is seen as 
the same size as the first. This doesn't occur when the order is reversed.

It's confusing. Is this expected? I'm using the latest btrfs-progs and Linux 
3.5.

Confusing it is, caused by this commit

Author:     Josef Bacik [off-list ref]
AuthorDate: Wed Mar 28 14:20:52 2012 -0400
Commit:     Chris Mason [off-list ref]
CommitDate: Tue Jul 3 16:27:46 2012 -0400

    btrfs-progs: enforce block count on all devices in mkfs

    I had a test that creates a 7gig raid1 device but it was ending up wonky
    because the second device that gets added is the full size of the disk
    instead of the limited size.  So enforce the limited size on all disks
    passed in at mkfs time, otherwise our threshold calculations end up wonky
    when doing chunk allocations.  Thanks,

Ooops, that's definitely not what I intended, I will fix that up right away,
sorry about that.  Thanks,

Josef