Ubuntu & Debian RAM Disk

March 22, 2016

Ubuntu & Debian RAM Disk

What is RAM Disk

A RAM disk or RAM drive is a block of RAM (primary storage or volatile memory) that a computer's software is treating as if the memory were a disk drive(secondary storage)

Why Use RAM disk

  • Speed
    RAM > SSD > HDD
  • Capacity & Price
    HDD > SSD > RAM

But we have more RAM[4GB]

How to make RAM disk

Use tmpfs

$shell > sudo mkdir /media/ramdisk
$shell > sudo mount -t tmpfs tmpfs /media/ramdisk

Mount on Start Up
Edit file /etc/fstab add to last line

tmpfs /media/ramdisk tmpfs defaults,mode=1 777 0 0

And reboot system

Squashfs!!

Compressed real-only file system for Linux. SquashFS compresses files , inodes and directories , and supports block sizes up to 1 MB for greater compression.
SquashFS is also free software(licensed under the GPL) for accessing SquashFS filesystems.SquashFS is intented for general real-only file system use and in comstrained block device/memory system ( e.g. embedded systems) where low overhead is needed.
The standrand version of SquashFS uses gzip compression , although there is also a project that brings LZMA compression to SquashFS.

Make squashfs file

Install squashfs tools

sudo apt-get install squashfs-tools

Create .sqsh file

mksquashfs /usr/lib/jvm/java-6-sun-1.6.0.21 /home/binkery/jdk6.sqsh

Unsquash

unsquashfs [option] target [file/directories to extract]

Make Java run In RAM

step 1. Create RAM disk

Use tmpfs

$shell > sudo mkdir /media/ramdisk
$shell > sudo mount -t tmpfs tmpfs /media/ramdisk

Mount on Start Up
Edit file /etc/fstab add to last line

tmpfs /media/ramdisk tmpfs defaul,mode=1 777 0 0

step 2. Create Java squashfs

Install squasfsh tools

sudo apt-get install squashfs-tools

create .sqsh file

mksquashfs /usr/lib/jvm/java-6-sun-1.6.0.21 /home/binkery/jdk6.sqsh

step 3. Mount Java to RAM

$shell > sudo mount /home/binkery/jdk6.sqsh /media/ramdisk -t squashfs -o loop

Make it permanant on startup
Edit /etc/fstab add line

/home/binkery/jdk6.sqsh /media/ramdisk squashfs ro,defaults,loop 0 0

step 4. Set Java to default

sudo update-alternatives --install "/usr/bin/java/" "/media/ramdisk/bin/java" 1

check install java complete

sudo update-alternatives --config java

And choose java in ram.

Finish.

--- EOF ---

评论

  1. Android Android

    加油!

添加新评论