Unpacking systemd (225-1ubuntu9) over (225-1ubuntu4) ...
dpkg: error processing archive /var/cache/apt/archives/systemd_225-1ubuntu9_amd64.deb (--unpack):
 unable to make backup link of './usr/bin/systemd-detect-virt' before installing new version: Cannot allocate memory
dpkg-deb: error: subprocess paste was killed by signal (Broken pipe)
addgroup: The group `systemd-journal' already exists as a system group. Exiting.
Errors were encountered while processing:
 /var/cache/apt/archives/systemd_225-1ubuntu9_amd64.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)