How to Increase swap memory size in Linux

You must have faced a condition when you need to increase your swap size. Well I faced one when I was trying to install Oracle Database and I was out of swap memory.

I will show you two ways which can be used to do the same.

Method 1


If you have additional space in your hard disk create swap based partition.
# fdisk /dev/sda
Command (m for help):
n
Command action
   e   extended
   p   primary partition (1-4)
e
Partition number (1-4): 1
First cylinder (1-48699, default 1): 1
Last cylinder, +cylinders or +size{K,M,G} (1-48699, default 48699): +100M
Command (m for help): p

Disk /dev/sda: 51.1 GB, 51064602624 bytes
64 heads, 32 sectors/track, 48699 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x3a369b23
Device    Boot      Start         End      Blocks   Id  System
/dev/sda4                    1         101      103408    5   Extended

Command (m for help): t
Selected partition 1
Hex code (type L to list codes): L
Hex code (type L to list codes): 82
Command (m for help):w
Once the partition is created run the below commands
# partprobe /dev/sda4
# mkswap /dev/sda4
To utilize the created partition as swap and making it "ON"
# swapon /dev/sda4
To check the swap report

# swapon -s
Ensure that when the system reboots, the swap file is made available to the kernel

# vi /etc/fstab
/dev/sda4                    swap                   swap     defaults        0 0
Update the fstab file
# mount -a
If you want to turnoff the swap partition
# swapoff
To check the swap partitions
# swapon -s
Check the swap memory
# free -m

Method 2
If you do not have additional space in your hard disk create swap based file.

Create 512MB swap file
dd if=/dev/zero of=/swapfile bs=1024 count=524288
Calculation:
For 512 MB = 512 * 1024
For 2 GB = (2*1024) * 1024
# mkswap /swapfile
# swapon /swapfile
Ensure that when the system reboots, the swap file is made available to the kernel

# vi /etc/fstab
/swapfile                    swap                   swap     defaults        0 0
Update the fstab file

# mount -a


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