If your system does not have /dev/full created already, it can be created with the following commands:
mknod -m 666 /dev/full c 1 7 chown root:root /dev/full
The file /dev/full has major device number 1 and minor device number 7.
Writes to the /dev/full device fail with an ENOSPC error. This can be used to test how a program handles disk-full errors.
Reads from the /dev/full device will return \0 characters.
Seeks on /dev/full will always succeed.
mknod(1), null(4), zero(4)