Description:
The kernel will refuse to mount a freshly created xfs filesystem with the default options.

According to http://comments.gmane.org/gmane.comp.file-systems.xfs.general/69514, the current version of xfsprogs enables the CRC and free inode BTree features by default.
The CRC feature was not completely implemented until kernel 3.16.

As a workaround, disable the features at format time: mkfs.xfs -m crc=0,finobt=0 /dev/blah

Is there a plan to move to the latest LTS kernel (3.18 at the moment)?


Additional info:
* package version(s)
linux-lts 3.14.51-1
xfsprogs 3.2.4-1

* commands, output and logs
# mkfs.xfs /dev/vg_fractal/postgres-backup
meta-data=/dev/vg_fractal/postgres-backup isize=512 agcount=16, agsize=8192000 blks
= sectsz=4096 attr=2, projid32bit=1
= crc=1 finobt=1
data = bsize=4096 blocks=131072000, imaxpct=25
= sunit=128 swidth=384 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal log bsize=4096 blocks=64000, version=2
= sectsz=4096 sunit=1 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0

# mount -v /dev/vg_fractal/postgres-backup /var/lib/postgres-backup
mount: wrong fs type, bad option, bad superblock on /dev/mapper/vg_fractal-postgres--backup,
missing codepage or helper program, or other error

In some cases useful info is found in syslog - try
dmesg | tail or so.

# dmesg|tail
[...]
[354456.918254] XFS (dm-16): Version 5 superblock detected. This kernel has EXPERIMENTAL support enabled!
Use of these features in this kernel is at your own risk!
[354456.918391] XFS (dm-16): Superblock has unknown read-only compatible features (0x1) enabled.
[354456.918461] XFS (dm-16): Attempted to mount read-only compatible filesystem read-write.
Filesystem can only be safely mounted read only.
[354456.918477] XFS (dm-16): SB validate failed with error 22.


Steps to reproduce:
With the current linux-lts and xfsprogs,
# mkfs.xfs /dev/blah
# mount /dev/... /mnt/pnt