Cant mount xfs lvm. Experimental Features?

[Marko Weber|8000]

Am 2015-08-26 00:58, schrieb Eric Sandeen:
> On 8/25/15 5:53 PM, Marko Weber|8000 wrote:
> 
>> eric,
>> i rebootet the machine and created a new logical volume.
>> i formatted the lv with mkfs.xfs
>> i tried to mount it on the new kernel:
>> 
>> Aug 26 00:47:17 backupserver kernel: XFS (dm-2): Version 5 superblock 
>> detected. This kernel has EXPERIMENTAL support enabled!
>> Aug 26 00:47:17 backupserver kernel: Use of these features in this 
>> kernel is at your own risk!
>> Aug 26 00:47:17 backupserver kernel: XFS (dm-2): Superblock has 
>> unknown read-only compatible features (0x1) enabled.
>> Aug 26 00:47:17 backupserver kernel: XFS (dm-2): Attempted to mount 
>> read-only compatible filesystem read-write.
>> Aug 26 00:47:17 backupserver kernel: Filesystem can only be safely 
>> mounted read only.
>> Aug 26 00:47:17 backupserver kernel: XFS (dm-2): SB validate failed 
>> with error 22.
> l
> http://xfs.org/index.php/XFS_FAQ#Q:_What_information_should_I_include_when_reporting_a_problem.3F
> ...
> 
>> this happens with the newly created logical volume.
>> 
>> the other 2 lvm partitions with xfs are fine.
>> 
>> any idea?
> 
> Without any actual information (i.e. kernel versions or userspace 
> version),
> I'll have to assume that you have recent xfsprogs which sets some 
> features by
> default which older kernels cannot understand.

ok, what info do you need?

on gentoo-linux:

xfsprogs: v 3.2.4 (Useflag, nls readline)
kernel:   3.14.51


> 
>> Aug 26 00:47:17 backupserver kernel: XFS (dm-2): Superblock has 
>> unknown read-only compatible features (0x1) enabled.
> 
> #define XFS_SB_FEAT_RO_COMPAT_FINOBT   (1 << 0)         /* free inode 
> btree */
> 
> mkfs.xfs with -m crc=0,finobt=0 to turn off these features if you have
> an older kernel which
> doesn't understand them.
> 
> -Eric