VACUUM FULL fails with 'ERROR: Check free disk space'

Question

I am using Postgres 9.4. I have a database that \l+ tells me is 164 GB. When I try to run VACUUM FULL on the database, I get this error (after many hours):

ERROR:  could not extend file "base/18222/20547.2": wrote only 4096 
        of 8192 bytes at block 279347
HINT:  Check free disk space.

I have 320GB of SSD on the server of which 89GB is available:

$ df -h
Filesystem                 Size  Used Avail Use% Mounted on
rootfs                     315G  211G   89G  71% /
udev                        10M     0   10M   0% /dev
tmpfs                      6.4G  192K  6.4G   1% /run
/dev/disk/by-label/DOROOT  315G  211G   89G  71% /
tmpfs                      5.0M     0  5.0M   0% /run/lock
tmpfs                       13G  4.0K   13G   1% /run/shm

I can't easily add more disk space to the server. Is there anything else I can do?

I found this question, so I can try that if needed. But I was wondering if I could tell VACUUM FULL to work with less memory.

Answer 1

According to postgresql documentation:

VACUUM FULL actively compacts tables by writing a complete new version of the table file with no dead space. This minimizes the size of the table, but can take a long time. It also requires extra disk space for the new copy of the table, until the operation completes.

So if you have one big table vacuum full can easily eat all your disk space. Maybe the best thing would be to do a full backup/restore - the result will be the same as if you did a vacuum full.