How to prevent tmpfs /tmp causing machine to run out of memory?

Question

I have a virtual server (Debian 8.5, OpenVZ) that seems to run out of memory* when tmpfs-based /tmp is about 60% full.

(* while the system reports 2GB of memory still free, processes start to behave erratically, /tmp writes fail with ENOSPC, forking fails with ENOMEM, some connections drop with ENOBUFS, and eventually sshd starts closing connections during handshake).

Is this normal for tmpfs, or is my system somehow horribly misconfigured?

Can it be fixed by shrinking size of /tmp?

How can I resize /tmp if it's not in /etc/fstab?

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 Filesystem Size Used Avail Use% Mounted on /dev/ploop25777p1 150G 19G 126G 13% / devtmpfs 2.0G 0 2.0G 0% /dev tmpfs 2.0G 0 2.0G 0% /dev/shm tmpfs 2.0G 17M 2.0G 1% /run tmpfs 5.0M 0 5.0M 0% /run/lock tmpfs 2.0G 0 2.0G 0% /sys/fs/cgroup tmpfs 2.0G 68K 2.0G 1% /tmp none 2.0G 0 2.0G 0% /run/shm 

 proc /proc proc defaults 0 0 none /dev/pts devpts rw,gid=5,mode=620 0 0 none /run/shm tmpfs defaults 0 0 

Answer 1

tmpfs is a filesystem in memory, that can hog your memory if you have a lot of tmp files that do not get cleaned up.

You can use the filesystem for /tmp by editing /etc/default/tmpfs and reboot.

But you should really find out why /tmp is filling up.

Edit: You can also limit the size in the file...