How to Increase the Size of the /tmp Folder on Linux

If Linux reports that /tmp is full, do not resize it blindly. First check what filesystem actually backs the directory. If /tmp is a tmpfs mount, you can raise its size limit immediately with a remount and make that limit persistent in /etc/fstab. If it is part of an ext4, XFS, Btrfs, or other disk-backed filesystem, the size= tmpfs option does not apply.

Check how /tmp is mounted

Open a terminal and run:

findmnt -T /tmp -o TARGET,SOURCE,FSTYPE,OPTIONS
df -hT /tmp

The findmnt command identifies the filesystem that contains /tmp, while df shows its size and current usage. The upstream findmnt documentation recommends using the target option to resolve the filesystem for a path.

If FSTYPE is tmpfs, continue with the steps below. If it is something such as ext4, xfs, or btrfs, skip to the disk-backed section.

Temporarily increase a tmpfs /tmp

You do not need to unmount /tmp. Linux tmpfs supports changing its maximum size during a remount without discarding the files already stored there. For example, to raise the limit to 5 GiB, run:

sudo mount -o remount,size=5G /tmp

Then verify the result:

df -h /tmp

The Linux kernel's tmpfs documentation states that the size= limit can be changed on remount. A value such as 5G is a capacity ceiling, not 5 GiB of RAM reserved immediately. tmpfs consumes memory as files are stored and can use swap when swap is available.

Do not set an unnecessarily huge limit. A workload that fills a large tmpfs can create severe memory pressure. Also, a remount like this is temporary: the original boot configuration returns after a reboot unless you change the persistent mount settings.

Make the larger /tmp size persistent

Only use this method after confirming that /tmp is meant to be tmpfs. Back up /etc/fstab first:

sudo cp /etc/fstab /etc/fstab.backup

Open the file with your preferred root-capable editor, for example:

sudoedit /etc/fstab

If an existing /tmp tmpfs line is present, keep its current security and compatibility options and change only its size= value. If your system uses systemd's default tmpfs-backed /tmp and has no /tmp entry in fstab, systemd documents that an /etc/fstab entry can be used to change the tmpfs mount options. A typical example is:

tmpfs /tmp tmpfs rw,nosuid,nodev,size=5G,mode=1777 0 0

The mode=1777 setting keeps the normal world-writable temporary-directory permissions with the sticky bit. Do not add options such as noexec just for resizing; changing unrelated mount behavior can break software that expects the existing configuration. See systemd's API file systems guidance and the upstream fstab documentation.

On a systemd-based distribution, reload generated units after editing fstab:

sudo systemctl daemon-reload

If /tmp is already mounted as tmpfs, you can apply the new fstab options immediately with:

sudo mount -o remount /tmp

Otherwise, reboot at a convenient time. Afterward, check both the mount options and capacity:

findmnt -T /tmp -o TARGET,FSTYPE,OPTIONS
df -h /tmp

What if /tmp is not tmpfs?

If findmnt shows that /tmp lives on your root filesystem or another disk-backed filesystem, there is no independent tmpfs limit to enlarge. You must free space or expand the underlying filesystem, partition, or logical volume. Another option is to point a specific program at a larger temporary directory if it honors TMPDIR:

mkdir -p "$HOME/tmp"
chmod 700 "$HOME/tmp"
TMPDIR="$HOME/tmp" your-command

systemd's temporary-directory guidance notes that software should use $TMPDIR when it is set and that /var/tmp is generally better suited to larger temporary data that should survive a reboot.

If you still get “No space left on device”

Check inode usage as well as byte usage:

df -h /tmp
df -i /tmp

A filesystem can run out of inodes even when it still has free bytes. Also investigate which application is producing the temporary data rather than repeatedly enlarging /tmp. Resizing is appropriate when the normal workload legitimately needs more temporary capacity, but uncontrolled growth is usually better fixed at its source.