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I hope many of you will agree that sometimes it’s really good idea to have some small amount of RAM mounted as a filesystem. It may be necessary when running some bash or perl script that handles, say, thousands of small files so it’s much more effective not to waste computer resources on reading/writing data on hard disk but keep those files directly in memory. This idea is known as Virtual RAM Drive or ramdisk and can be setup in Ubuntu or almost any other Linux distribution using the following commands under root (to become root in Ubuntu use "sudo -s“):
# mkdir /tmp/ramdisk; chmod 777 /tmp/ramdisk
# mount -t tmpfs -o size=256M tmpfs /tmp/ramdisk/
where 256M is amount of RAM you wish to allocate for ramdisk. It’s clear that this value should be less than amount of free memory (use “free -m“). BTW, if you specify too many MBs for ramdisk Linux will try to allocate it from RAM and then from swap so resulting performance would be very poor.
1# mkdir /tmp/ramdisk; chmod 777 /tmp/ramdisk
2# mount -t tmpfs -o size=256M tmpfs /mnt/tmpfs/
what is the purpose of line 1, if we mount ramdisk on /mnt/tmpfs on line 2?
Thanks, GhostOrchid — I fixed the typo.
Ubuntu by default already has /dev/shm mounted as tmpfs. If you really like the name /tmp/ramdisk, you can just do:
1# ln -s /dev/shm/ /tmp/ramdisk
If the name isn’t all that important to you, just use /dev/shm directly.
This is a seriously handy tip if you are using an SSD drive and wish to minimise the read / write access during heavy scripts.. Top!
why would there be ram0 -ram15 in /dev why would you need to make more how do you edit these?