Increase or add SWAP memory in Linux

Hello Everyone,

Today we are going to increase Swap partition our Linux Machine :-

First We have to know what is Swap ? :- 🙂

Simply Swap space in Linux is used when the amount of physical memory (RAM) is full, We can use our HDD space as RAM (Virtual memory).

 

 

Lets start Increase space space :-

 

 First Check your partition in Your HDD:- 

[root@sahil ~]# fdisk -l<====== Check list the partition

Disk /dev/sda: 80.0 GB, 80026361856 bytes

255 heads, 63 sectors/track, 9729 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System

/dev/sda1 * 1 25 200781 83 Linux

/dev/sda2 26 5124 40957717+ 83 Linux

/dev/sda3 5125 5389 2128612+ 82 Linux swap / Solaris

 

As you can see above i have 3 partitions in my Hard Drive

Now I’m going to create a new partition(Swap) by using fdisk:-

 

[root@sahil ~]# fdisk /dev/sda

The number of cylinders for this disk is set to 9729.

There is nothing wrong with that, but this is larger than 1024,

and could in certain setups cause problems with:

1) software that runs at boot time (e.g., old versions of LILO)

2) booting and partitioning software from other OSs

(e.g., DOS FDISK, OS/2 FDISK)

Command (m for help): n <======== New partition and For help just press m

 

Command action

e extended

p primary partition (1-4)

p

Selected partition 4

First cylinder (5390-9729, default 5390): <===== Just press Enter

Using default value 5390

Last cylinder or +size or +sizeM or +sizeK (5390-9729, default 9729): +1G <=== Size of Swap parttition here size is 1GB

 

 

 

Command (m for help): l <======== list known partition types

0 Empty 1e Hidden W95 FAT1 80 Old Minix bf Solaris

1 FAT12 24 NEC DOS 81 Minix / old Lin c1 DRDOS/sec (FAT-

2 XENIX root 39 Plan 9 82 Linux swap/ So c4 DRDOS/sec (FAT-

3 XENIX usr 3c PartitionMagic 83 Linux c6 DRDOS/sec (FAT-

4 FAT16 <32M 40 Venix 80286 84 OS/2 hidden C: c7 Syrinx

5 Extended 41 PPC PReP Boot 85 Linux extended da Non-FS data

6 FAT16 42 SFS 86 NTFS volume set db CP/M / CTOS / .

7 HPFS/NTFS 4d QNX4.x 87 NTFS volume set de Dell Utility

8 AIX 4e QNX4.x 2nd part 88 Linux plaintext df BootIt

9 AIX bootable 4f QNX4.x 3rd part 8e Linux LVM e1 DOS access

a OS/2 Boot Manag 50 OnTrack DM 93 Amoeba e3 DOS R/O

b W95 FAT32 51 OnTrack DM6 Aux 94 Amoeba BBT e4 SpeedStor

c W95 FAT32 (LBA) 52 CP/M 9f BSD/OS eb BeOS fs

e W95 FAT16 (LBA) 53 OnTrack DM6 Aux a0 IBM Thinkpad hi ee EFI GPT

f W95 Ext’d (LBA) 54 OnTrackDM6 a5 FreeBSD ef EFI (FAT-12/16/

10 OPUS 55 EZ-Drive a6 OpenBSD f0 Linux/PA-RISC b

11 Hidden FAT12 56 Golden Bow a7 NeXTSTEP f1 SpeedStor

12 Compaq diagnost 5c Priam Edisk a8 Darwin UFS f4 SpeedStor

14 Hidden FAT16 <3 61 SpeedStor a9 NetBSD f2 DOS secondary

16 Hidden FAT16 63 GNU HURD or Sys ab Darwin boot fb VMware VMFS

17 Hidden HPFS/NTF 64 Novell Netware b7 BSDI fs fc VMware VMKCORE

18 AST SmartSleep 65 Novell Netware b8 BSDI swap fd Linux raid auto

1b Hidden W95 FAT3 70 DiskSecure Mult bb Boot Wizard hid fe LANstep

1c Hidden W95 FAT3 75 PC/IX be Solaris boot ff BBT

 

Command (m for help): p<======print the details of all Partition

Disk /dev/sda: 80.0 GB, 80026361856 bytes

255 heads, 63 sectors/track, 9729 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System

/dev/sda1 * 1 25 200781 83 Linux

/dev/sda2 26 5124 40957717+ 83 Linux

/dev/sda3 5125 5389 2128612+ 82 Linux swap / Solaris

/dev/sda4 5390 5512 987997+ 83 Linux

 

 

 

 

Command (m for help):t     <=====change a partition’s system id

 

Partition number (1-4): 4  <==== Partition No.

Hex code (type L to list codes):82<========Hexa code for Linux Swap partition

Changed system type of partition 4 to 82 (Linux swap / Solaris)

Command (m for help):w <========== to write the configuration in the partition table

The partition table has been altered!

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: Device or resource busy.

The kernel still uses the old table.

The new table will be used at the next reboot.

Syncing disks

 

[root@sahil ~]# partprobe

[root@sahil ~]# mkswap /dev/sda4<=========== Formats partition to be used as a swap device

Setting up swapspace version 1, size = 1011703 kB

 

 

Note: if we restart Linux Machine then the new swap partition will get lost so we need to make it permanent by making an entry in /etc/fstab

 

[root@sahil ~]# vim /etc/fstab<============Entry swap partition in fstab file

LABEL=/ / ext3 defaults 1 1

LABEL=/boot /boot ext3 defaults 1 2

tmpfs /dev/shm tmpfs defaults 0 0

devpts /dev/pts devpts gid=5,mode=620 0 0

sysfs /sys sysfs defaults 0 0

proc /proc proc defaults 0 0

LABEL=SWAP-sda3 swap swap defaults 0 0

 

/dev/sda4 swap swap defaults 0 0 <====== Entry of Newly created Swap partition

 

 

wq! <=========== Save and Quit

 

 

[root@sahil ~]# mount -a <======update fstab entry

 

 

[root@sahil ~]# swapon -a

 

Now Check Swap Status:-

 

[root@sahil ~]# swapon -s<=========displays the current swap space in KB.

Filename Type Size Used Priority

/dev/sda3 partition 2128604 0 -1

/dev/sda4 partition 987988 0 -2 <======== New Swap Partition 🙂

 

We have created swap partition successfully 🙂

 

Thank You !! 🙂

Enjoy Linux-Ing 🙂 🙂 🙂