/tmp mounted with only 1MB space, 100% used, as filesystem "overflow"

Question

For some reason, my /tmp is said to be 100% used.

root$ df 
Filesystem         1K-blocks        Used  Available Use% Mounted on
overflow                1024        1024          0 100% /tmp
... other stuff ...

Output of running df -h

$ df -h
Filesystem        Size  Used Avail Use% Mounted on
/dev/sda1         102G   72G   25G  75% /
none              4.0K     0  4.0K   0% /sys/fs/cgroup
udev              7.8G  4.0K  7.8G   1% /dev
tmpfs             1.6G  844K  1.6G   1% /run
none              5.0M     0  5.0M   0% /run/lock
none              7.8G  240K  7.8G   1% /run/shm
none              100M   16K  100M   1% /run/user
overflow          1.0M  1.0M     0 100% /tmp

Is there any way to safely remove unused stuff in /tmp?

Thanks

Answer 1

This is bizarre, you should have a partition name like "/dev/sda4" instead of "overflow" in the first column of a df output associated with /tmp, or possibly no entry at all.... I've never seen this "overflow" before.

Googling "filesystem overflow tmp" found a bunch of similar cases.

The first link http://jarrodoverson.com/blog/overflow-filesystem-in-linux/ says

If your “/tmp” mount on a linux filesystem is mounted as overflow (often sized at 1MB), this is likely due to you not specifying “/tmp” as its own partition and your root filesystem filled up and “/tmp” was remounted as a fallback. To fix this after you’ve cleared space, just unmount the fallback and it should remount at its original point:

sudo umount overflow