Reverting df438af seems to have fixed it.
$ cat /proc/version_signature Ubuntu 3.2.0-86.123~lp1465322Commitdf438afReverted-generic 3.2.69
$ df | head -3 Filesystem 1K-blocks Used Available Use% Mounted on /dev/vda1 7481832 4735296 2366480 67% / udev 371924 4 371920 1% /dev
Reverting df438af seems to have fixed it.
$ cat /proc/version_ signature 123~lp1465322Co mmitdf438afReve rted-generic 3.2.69
Ubuntu 3.2.0-86.
$ df | head -3
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/vda1 7481832 4735296 2366480 67% /
udev 371924 4 371920 1% /dev