Btrfs test fails on Ubuntu 14.04

Server
1

Hi.
I’m trying to setup UrBackup server on Ubuntu 14.04 with LVM/btrfs. Got an error with urbackup_snapshot_helper test:

# cat /etc/*-release | grep -i desc
DISTRIB_DESCRIPTION=“Ubuntu 14.04.5 LTS”

# uname -a
Linux server1 3.13.0-93-generic #140-Ubuntu SMP Mon Jul18 21:21:05 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

# aptitude show urbackup-server | grep -i version
Version: 2.0.32.1563-1ubuntu1~trusty

# cat /etc/urbackup/backupfolder
/srv/urbackup

# mount | grep btrfs
/dev/mapper/vg_test-lv_test on /srv/urbackup type btrfs (rw,compress=lzo)

# ls -la /srv/urbackup
total 20
drwxr-xr-x 1 urbackup urbackup 52 Aug 16 15:01 .
drwxr-xr-x 3 root root 4096 Aug 15 11:01 …
drwxr-x— 1 urbackup urbackup 594 Aug 16 03:41 urbackup
drwxr-x— 1 urbackup urbackup 0 Aug 16 01:43 urbackup_tmp_files

# urbackup_snapshot_helper test
Create subvolume ‘/srv/urbackup/testA54hj5luZtlorr494/A’
Create a snapshot of ‘/srv/urbackup/testA54hj5luZtlorr494/A’ in ‘/srv/urbackup/testA54hj5luZtlorr494/B’
ERROR: error accessing ‘-c’
Delete subvolume ‘/srv/urbackup/testA54hj5luZtlorr494/A’
TEST FAILED: Removing subvolume A failed
ERROR: error accessing ‘-c’
Delete subvolume ‘/srv/urbackup/testA54hj5luZtlorr494/B’
TEST FAILED: Removing subvolume B failed

What’s may be wrong?

2

btrfs subvolume delete /srv/urbackup/testA54hj5luZtlorr494/A has a non-zero return code for some reason.

3

As far as I see, error rising on snapshot creating, before subvolume deleting.
Or “error accessing ‘-c’” message is not fatal?