Search code examples
linuxshared-memory

How to resize /dev/shm?

On Ubuntu 18.04, When I run

$ df -h,

I see this result:

Filesystem      Size  Used Avail Use% Mounted on
...
tmpfs           3,9G   73M  3,8G   2% /dev/shm
...

/dev/shm has a 3.9G size.

How could I change the size of /dev/shm?

Solution
    1. Edit file /etc/fstab (with sudo if needed).
    2. In this file, try to locate a line like this one : none /dev/shm tmpfs defaults,size=4G 0 0.

    Case 1 - This line exists in your /etc/fstab file:

    • Modify the text after size=. For example if you want an 8G size, replace size=4G by size=8G.
    • Exit your text editor, then run (with sudo if needed) $ mount -o remount /dev/shm.

    Case 2 - This line does NOT exist in your /etc/fstab file:

    • At the end of the file, append the line none /dev/shm tmpfs defaults,size=4G 0 0, and modify the text after size=. For example, if you want an 8G size, replace size=4G by size=8G.
    • Exit your text editor, then run (with sudo if needed) $ mount /dev/shm.