Why bind-mount /var/tmp to /tmp?

Question

I've read in several places that it is recommended to bind-mount /var/tmp to /tmp. This can be done by adding the following line to /etc/fstab:

/tmp /var/tmp none rw,noexec,nosuid,nodev,bind 0 0

How can this be beneficial? In other words why should we bind-mount /var/tmp to /tmp ?

Answer 1

The Filesystem HierarchyStandard says:

• /tmp/ Temporary files. Often not preserved between system reboots.
• /var/tmp/ Temporary files to be preserved between reboots.

For example: if an processus is launched every 5 minutes and needs to store some data between every launch, it will rather store them in /var/tmp/.