The disk is empty and the file will not be created

The queue service cannot write a single new file. The log repeats one line: "No space left on device". The on-call engineer looked at the disk, saw it was empty, and stopped there.

The symptom

There are a full 64 MB free on /tmp, and even an empty file will not be created.

$ df -h /tmp
Filesystem      Size  Used Avail Use% Mounted on
tmpfs            64M  8.0K   64M   1% /tmp

$ touch /tmp/hello
touch: cannot touch '/tmp/hello': No space left on device

The error message is not lying. The "space" it means is simply not the space df -h reports.

What you have to end up with

Three conditions. A file can be created on /tmp again. There are at least five hundred free inodes there, so the headroom l