I am trying to setup a Urbackup server on Centos 7 but it fails the btrfs test with the following output
[root@server4 disk2]# urbackup_snapshot_helper test
Testing for btrfs...
Create subvolume '/disk2/urbackup/testA54hj5luZtlorr494/A'
Create a snapshot of '/disk2/urbackup/testA54hj5luZtlorr494/A' in '/disk2/urbackup/testA54hj5luZtlorr494/B'
TEST FAILED: Creating cross sub-volume reflink failed. Need Linux kernel >= 3.6.
Delete subvolume (commit): '/disk2/urbackup/testA54hj5luZtlorr494/A'
Delete subvolume (commit): '/disk2/urbackup/testA54hj5luZtlorr494/B'
It appears that the test program can create the snapshots but not the cross snapshot link. However my kernel version is 3.10 which is greater than the minimum supported version 3.6 mentioned in the output.
[root@server4 disk2]# uname -r
I am using urbackup-server-18.104.22.1685-2.2.x86_64 and btrfs-progs-4.9.1-1.el7.x86_64
I would be grateful if anyone can suggest a way around this problem. Urbackup-server works fine for me but is not using it's btrfs mode and therefore I don't get the benefits of the snapshotting file backup mode which I am particularly interested in.