On Fri, Apr 10, 2015 at 08:53:22AM +1000, Dave Chinner wrote: > On Thu, Apr 09, 2015 at 06:20:26PM -0400, Joe Landman wrote: > > > > > > On 04/09/2015 06:18 PM, Dave Chinner wrote: > > >On Thu, Apr 09, 2015 at 05:02:33PM -0400, Joe Landman wrote: > > >>If I build an MD raid0 with a non power of 2 chunk size, it appears > > >>that I can mkfs.xfs a file system, but it doesn't show up in blkid > > >>and is not mountable. Yet, using a power of 2 chunk size, this does > > >>work correctly. This is kernel 3.18.9. > > >> > > > > [...] > > > > >That looks more like a blkid or udev problem. try using blkid -p so > > >that it doesn't look up the cache but directly probes devices for > > >the signatures. strace might tell you a bit more, too. And if the > > >filesystem mounts, then it definitely isn't an XFS problem ;) > > > > Thats the thing, it didn't mount, even when I used the device name > > directly. > > Ok, that's interesting. Let me see if I can reproduce it locally. If > you don't hear otherwise, tracing would still be useful. Thanks for > the bug report, Joe. No luck - md doesn't allow the device to be activated on 4.0-rc7: $ sudo mdadm --version mdadm - v3.3.2 - 21st August 2014 $ uname -a Linux test4 4.0.0-rc7-dgc+ #882 SMP Fri Apr 10 08:50:52 AEST 2015 x86_64 GNU/Linux $ sudo wipefs -a /dev/vd[ab] /dev/vda: 4 bytes were erased at offset 0x00001000 (linux_raid_member): fc 4e 2b a9 /dev/vdb: 4 bytes were erased at offset 0x00001000 (linux_raid_member): fc 4e 2b a9 $ sudo mdadm --create /dev/md20 --level=0 --metadata=1.2 --chunk=1152 --auto=yes --raid-disks=2 /dev/vd[ab] mdadm: RUN_ARRAY failed: Invalid argument Problem may be that chunk size is not a power of 2 $ cat /proc/mdstat Personalities : [raid1] [raid10] [raid6] [raid5] [raid4] unused devices: <none> $ So I can't actually reproduce what you are seeing because MD doesn't allow the device to be activated and so mdadm tears it back down. Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html