In this article, you will learn that how to create swap. There are three types of swap that will be covered in this article respectively.

• Standard SWAP
• LVM SWAP
• SWAP File

Create Standard SWAP

Command to see available RAM and SWAP stats

# free -h

# swapon -s

Step 1: Follow below instructions

• List partition table using below command
  

  # fdisk -l

• Choose desired hard disk for swap partition List partition table using below command

  # fdisk /dev/sdb

• Press m for help
• Press p to print partition table
• Press n to create new partition
• Press p to make primary partition.
• Press 1 to create first partition on selected disk.
  There are 1-4 partition number. We can type any one number from them.
• Press enter to leave first cylinder as default
• Now assign space to partition. Use + to assign space e.g.
  +1G and press enter.
• Press p to print partition table.
• Now set SWAP file system ID on partition.
• Press l to list all available file system volumes. We will set SWAP (82)
• Press t to set file system on partition
• Press 1 to select partition. It is the partition on which we set SWAP file system.
• type 82 and press enter to set LVM ID on selected partition.
• Press w to write/save partition.

Now run command to make changes in partition table using below command

# partprobe

Step 2: Format Partition (File System)

# mkswap   /dev/sdb1

Step 3: Set Partition Label

Command to set Label on SWAP Partition
Syntax:  mkswap   -L   Label-name    /dev/partition

# mkswap   -L   myswap    /dev/sdb1

Step 4: Now Mount partition in /etc/fstab File

# vim /etc/fstab

and add following entry:

LABEL=myswap           swap    swap    deafults    0     0

write changes to /etc/fstab and quite

Step 5: Now Activate Created SWAP

# swapoff  -a              (Disable all swap)

# swapon  -a               (enable all swap)

# swapon  -s               (list enabled all swap)

# free   -m

You have created a standard swap successfully!

LVM SWAP

Step 1: Follow the Previous procedure

Step 2: Follow the Previous procedure

Step 3: Create PV (Physical Volume) of the partition

Use below command

#pvcreate   /dev/sdb1

#pvs

Step 4: Create VG (Volume Group)

#vgcreate   swap_vg    /dev/sdb1

#vgs

Note: swap_vg is vg name you can use any

Step 5: Create LVM (Logical Volum Manager)

Use below command

# lvcreate   -l   100%free   -n    swap_lvm   swap_vg
# lvs

swap_lvm   is the LVM Name. you can use any.

swap_vg     is the name of created VG

Step 6: Format Partition (File system)

# mkswap   /dev/swap_vg/swap_lvm

Step 7: Mount Partition in /etc/fstab File

# vi /etc/fstab

and add the following entry:

/dev/swap_vg/swap_lvm  swap  swap  defaults 0 0

write changes to /etc/fstab and quite

Step 8: Now Activate Created SWAP

# swapoff  -a              (Disable all swap)

# swapon  -a               (enable all swap)

# swapon  -s               (list enabled all swap)

# free   -m

Make SWAP FILE

Step 1: Make File

We will create swap file of 3GB

Use the following command

# dd if=/dev/zero of=/myswap bs=1G count=3

Note: Above command will take some time to generate the file.

Step 2: Set Permission on SWAP File

set the appropriate permissions on the file to make it readable only by root user.

# cd /

# chmod   600   /myswap

# ls –lh myswap

Step 3: Set SWAP Filesystem on file

# mkswap /myswap

Step 4: Enable SWAP File

# swapon  /myswap

Step 5: Mount SWAP File in /etc/fstab file

# vi /etc/fstab

and add following entry:

/myswap  swap  swap  defaults 0 0

write changes to /etc/fstab and quite

Step 6: Now Activate Created SWAP

# swapoff  -a              (Disable all swap)

# swapon  -a               (enable all swap)

# swapon  -s               (list enabled all swap)

# free   -m

You have learned that how to create different types of SWAP in Linux.

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