"You don't need a ""ramdisk"". And in my opinion, Linux's ramdisk support sucks... needing to set up kernel parameters, etc.. to get a proper large size. The only advantage to a ""ramdisk"" is you can partition it, refer to it like a hard disk device (eg. in an fdisk command, a dd command, etc.). You want tmpfs, which is a file system running on RAM (or swap) without all the disk device stuff in between. Just simply add what you expected to find in your /etc/fstab, then mount it.
choose whichever editor you like, one of the following for example: sudo pico -w /etc/fstab sudo vim /etc/fstab
And personally, I don't really like tmpfs on my /tmp... it runs out of space too fast. And with the built in automatic file caching on ext, you don't really need tmpfs anyway (except for writing large things, but then you fill up the disk... so what is the point?)."