tmpfs

FreeBSD offers two mechanisms for a memory based /tmp filesystem: tmpmfs and tmpfs

tmpmfs simply sets up a fixed sized ramdisk using 'md' and mounts it as /tmp.

tmpfs provides a similar mechanism to Solaris, in that it uses virtual memory (RAM and swap) to provide a temporary filesystem. This facility is still considered experimental in FreeBSD 8.0-RELEASE, so it probably shouldn't be used on mission critical systems. I've not had any problems with it however.

To enable tmpfs, you just need to load the kernel module at boot, and add a line to /etc/fstab:

# cat /boot/loader.conf
tmpfs_load="YES"
# grep tmpfs /etc/fstab
tmpfs           /tmp            tmpfs   rw,mode=01777   0       0

The 'mode=01777' mount option ensures that the /tmp mount point directory has the correct permissions

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