There's two probably issues. 1) your root partition is full, and 2) you have /tmp mounted as a RAM disk, and so you are out of RAM.
To determine which problem you face, use the df command:
$ df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 16G 0 16G 0% /dev
tmpfs 16G 126M 16G 1% /dev/shm
tmpfs 6.3G 2.0M 6.3G 1% /run
/dev/nvme0n1p3 120G 39G 81G 33% /
tmpfs 16G 79M 16G 1% /tmp
/dev/nvme0n1p2 976M 425M 485M 47% /boot
/dev/nvme0n1p1 599M 78M 522M 13% /boot/efi
/dev/mapper/ebhomeVg01-home 512G 107G 405G 21% /home
tmpfs 3.2G 152K 3.2G 1% /run/user/1001
Here we can see that my root partition
/
has 39 G of 120 G free, and
/tmp
has a filesystem type of
tmpfs
, which means its held in RAM, not on a physical disk. If you do not have a /tmp filesystem in the output for your system, then it means that /tmp will be sharing space with your root partition.
If you are using tmpfs for /tmp, and it is full, then the quickest way to recover the space would be to reboot your system. Be aware that this means that anything held in /tmp will be gone, so if you are storing stuff in /tmp that you will need later, copy it somewhere else (like your home directory) first. In general, its a bad idea to store anything not of a temporary or "scratch" nature in /tmp, as the system does see it as
temporary and is free to remove files and data as it sees fit. I
have seen this happen.
If you are not using tmpfs for /tmp, and your root partition is full, then you will need to find out where all your space has gone. I like to use the
du
command for this. As root,
cd /
then do an ls and then
du -sh dir1 dir2 dir3 ...
where
dir1 dir2, etc are directories NOT listed in the output to df. This should produce something like
# du -sh etc mnt opt root usr var
46M etc
0 mnt
1.1G opt
852M root
33G usr
3.8G var
Which will show you the disk usage of the directories. If you wanted to take a further look at /opt, for example, you could then
# cd /opt
# du -sh * .??*
This will break down the disk usage for all the files and directoris in /opt, including hidden files and directories (e.g. .config, or .local). You should be able to find out what's consuming your disk space, and then make decisions about what to remove. That might not be obvious - there are some large files that are needed by the OS to run, so don't remove them. In general you will be looking for files that are owned by you, or are log files that can be trimmed and/or removed.