/var/tmp are expected to be persistent across reboots. From the
The /var/tmp directory is made available for programs that require temporary
files or directories that are preserved between system reboots. Therefore,
data stored in /var/tmp is more persistent than data in /tmp.
/var/tmp are often cache files or temporary files that should not
disappear in the event of a sudden power failure. They cannot be expected to
live forever though. It is common to clear old
/var/tmp on a
Here are some examples of
In summary, your system is unlikely to incur severe damage if you mount
as a tmpfs. Doing so may be undesirable though as you would risk
losing information to power failures and reboots.