Other tmpfs vs md

[Alain De Vos]

Are tempfilesystem tmpfs and memory-devices md more or less the same that they only exist in memory ?

 

[SirDice]

md(4)/mdconfig(8) can also be used to mount images (CD or disk images for example), not just memory disks, tmpfs(5) is specifically meant as a dynamically sized memory filesystem.

 

[mer]

md(4)/mdconfig(8) can also be used to mount images (CD or disk images for example), not just memory disks,

This is a very useful point to remember. I know for a fact that mounting an ISO over a md has saved my butt on a couple of occasions.
Sorry for the minor hijack.

 

[mtu]

tmpfs just gives you a filesystem for files. md gives you a GEOM that you can you can use like any block device: format it to some filesystem, encrypt it with GELI, even set up zpools on several md devices. It's nice for playing around and testing.