Usability of /dev/sda1 -- /mnt/

[matejvasek]

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Hi,

I was debugging no space left on device in one of my actions. I tried to run df -h in the GH Action.

Filesystem      Size  Used Avail Use% Mounted on
/dev/root        73G   52G   21G  72% /
tmpfs           7.9G  172K  7.9G   1% /dev/shm
tmpfs           3.2G  1.1M  3.2G   1% /run
tmpfs           5.0M     0  5.0M   0% /run/lock
/dev/sda15      105M  6.1M   99M   6% /boot/efi
/dev/sdb1        74G  4.1G   66G   6% /mnt
tmpfs           1.6G   12K  1.6G   1% /run/user/1001

What is this /mnt disk? It has a lot of free disk space I could use. Is it possible/safe? Any downsides to it? Why it is not employed by default (beside the swap file)?

[devinrsmith]

I came across /mnt as well investigating disk space issues. I see that apache/flink#24304 is using /mnt to gain additional space, but I don't see any documentation relating to it, so it feels like a "hack". The only references I can find to /mnt are actions/runner-images#965 / https://github.com/actions/runner-images/blob/ubuntu22/20240730.2/images/ubuntu/scripts/build/configure-environment.sh#L22-L25. It would be to get some clarification on the usability of /mnt.