RAM disk

  • RAM Disk is a portion which is used like physical storage.
  • any data stored on RAM disk is lost when system is shut down or powered off, So RAM disk is great place to put the temporary data.
  • Generally, RAM based file system is two types. one is rampfs, the other is tmpfs.

command to make RAMdisk on CentOS 7

$ mount -t tmpfs -o size=2G tmpfs /directory position

for example

$ mkdir ramdisk
$ mount -t tmpfs -o size=2G tmpfs ./ramdisk

What is the differenc between ramdfs and tmpfs

Primarily both ramfs and tmpfs does the same thing with few minor difference.

  • RAMFS will grow dynamically : So you need control the process that wirtes the date to make sure ramfs doesn’t go above the abailable RAM size in the system.

  • Tmpfs will not grow up dynamically : It would not allow you to write more that the size you’ve specified while mounting the tmpfs.

  • Tmpfs uses Swap

  • but RAMFS doesn’t use swap

procedure after getting a new device

  1. this is juse option, you have to get partition from a storage device.

fdisk or anther command

  1. you have to make file system format.

mkfs

  1. and then you have to mount device some directory.

mount

Appendix

Just I found out mkramdisk command on IBM AIX

But I cannot find that command in CentOS 7

   $ mkramdisk 
bash: mkramdisk: command not found...

Reference

Linux Ramdisk mini-HowtO

How to Use tmpfs on RHEL / CentOS 7.0

The geeks stuff