Backup/Snapshot fails

Hi

I currently have a zenoss 5.0.4, and i need to perform a backup, but i can't:

Exporting snapshots for Zenoss.core (bh7jblh6c6uemsv4nbezubd7r)
Mounting tenantID: bh7jblh6c6uemsv4nbezubd7r; baseDir: /opt/serviced/var/volumes
Mounting tenantID: bh7jblh6c6uemsv4nbezubd7r; baseDir: /opt/serviced/var/volumes
Performing snapshot rsync command: /usr/bin/rsync [-a /opt/serviced/var/volumes/bh7jblh6c6uemsv4nbezubd7r/ /opt/serviced/var/volumes/bh7jblh6c6uemsv4nbezubd7r_20151028-143421/]
Purging logstash entries older than 0 days
Deleting snapshots older than SERVICED_SNAPSHOT_TTL.
Mounting tenantID: bh7jblh6c6uemsv4nbezubd7r; baseDir: /opt/serviced/var/volumes
Could not perform rsync: rsync: writefd_unbuffered failed to write 5 bytes to socket [generator]: Broken pipe (32)
rsync error: error in rsync protocol data stream (code 12) at io.c(1532) [generator=3.0.9]
Could not snapshot service Zenoss.core (bh7jblh6c6uemsv4nbezubd7r): signal: killed
Could not snapshot service bh7jblh6c6uemsv4nbezubd7r: signal: killed
Could not export snapshot for Zenoss.core (bh7jblh6c6uemsv4nbezubd7r): signal: killed
Unexpected error during backup status: signal: killed

My disks:
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos_zentoss5-root 5.8G 2.3G 3.6G 40% /
devtmpfs 16G 0 16G 0% /dev
tmpfs 16G 0 16G 0% /dev/shm
tmpfs 16G 17M 16G 1% /run
tmpfs 16G 0 16G 0% /sys/fs/cgroup
/dev/sdb 10G 8.0G 2.1G 80% /opt/serviced/var/isvcs
/dev/sda1 497M 177M 321M 36% /boot
/dev/sde 16G 6.9G 8.9G 44% /opt/serviced/var/volumes
/dev/sdc 15G 6.8G 8.3G 46% /var/lib/docker
/dev/sdd 16G 33M 16G 1% /opt/serviced/var/backups

Before, i had insuficient space in the /volumes partition, and since the backup exports stuff there before using the backup folder, i guessed it was crashing because of that.
Now it is not the case (i think, because when the backups failed before, i got my volumes partition filled up).

No googling was able to help me.