dotfiles/notes/linux/ramdisks.md
2022-09-07 22:24:18 -06:00

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Ramdisks

Ram is fast and files sometimes need to be quick. Disks via ramfs and tmpfs allow us to mount a file system entirely in the ram, and it's supported by the linux kernel out of the box

Tmpfs is the newer version of ramfs, with the only difference being that tmpfs has a maximum size that it won't exceed. Ramfs doesn't actually bound its own size, so the system can run out of memory

# mount -t tmpfs -o uid=1000,size=1g tmpfs /home/emiliko/mnt

Mounts a temporary file system with a maximum size of 1GB at ~/mnt. Ramdisks only use the size they need, so mounting this blank file system won't take up any ram at first

Unmounting a ramdisk will clear everything off, which happens every time the system is powered off

Linux systems come with a /dev/shm directory by default, which is a ramdisk accessible by all users. To find the size of a ramdisk use df -h /dev/shm. To check which ramdisks are mounted, use findmnt or mount

For more information: