Ubuntu – How is the /tmp directory cleaned up

filesystemtmp

How is the /tmp directory cleaned up? Is it automatic? If so, how frequently is it cleaned up?

Best Answer

Note! This answer is outdated since at least ubuntu 14.04. See other answers for current situation and if they prove correct then upvote them furiously. Also post comment so I can put link here to current correct answer.

For 14.04 see https://askubuntu.com/a/759048/1366

For 16.10 see https://askubuntu.com/a/857154/453746

Old answer from 2011:

The cleaning of /tmp is done by the upstart script /etc/init/mounted-tmp.conf. The script is run by upstart everytime /tmp is mounted. Practically that means at every boot.

The script does roughly the following: if a file in /tmp is older than $TMPTIME days it will be deleted.

The default value of $TMPTIME is 0, which means every file and directory in /tmp gets deleted. $TMPTIME is an environment variable defined in /etc/default/rcS.

Related Solutions

Ubuntu – Good filesystem for /tmp

I sometimes find moving /tmp to ram (tmpfs) is the best solution (Especially on my setups which use a lot of disk intensive IO stuff - MySQL, etc) if you have enough RAM to feed it.

Ubuntu – How to encrypt the /tmp directory

The correct incantation in crypttab should look like this:

crypttmp /dev/mapper/vg_doulos-tmp /dev/urandom precheck=/bin/true,tmp,size=256,hash=sha256,cipher=aes-cbc-essiv:sha256

The most important part was the precheck=/bin/true. The reason why /tmp wasn't mounting was that cryptsetup was failing due to a precheck. The precheck noticed that the LVM partition was formatted for ext4 and refused to continue.

The fstab entry should look like this:

/dev/mapper/crypttmp /tmp ext4 defaults 0 2

Best Answer

Related Solutions

Ubuntu – Good filesystem for /tmp

Ubuntu – How to encrypt the /tmp directory

Related Question