Sunday, March 08, 2009

Linux: creating ramdisk

The following comes from tip #45.

Remember the old days of RAM disks? Well, Linux has them too! If you've never tried them, a RAM disk is a virtual filesystem that runs entirely from your PC's main memory, which means it's lightning fast to read and write anything you want.

How much space you choose to allocate to your RAM disk is down to how much RAM you have and how much you plan to use it - if you have 1GB of RAM, you can easily spare 64MB for a ramdisk; if you have 2GB you can probably spare 256MB, and if you're lucky enough to have 4GB then you can easily stretch your RAM disk legs with 1GB.

Here's how to set up a 64MB disk - just change the 65536 for the size you want:mkfs -t ext3 -q /dev/ram1 65536
mkdir -p /ramdisk
mount /dev/ram1 /ramdisk -o defaults,r,w
or mkdir /ramdisk
mount none -t tmpfs -o size=256M /ramdisk
That will allocate 256MB of space to your RAM disk. If you skip the "-o size=256M" part, half your RAM will be used by default.