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How to create and remove swap memory in CLI on Debian 11.3

To Create And Remove Swap Memory In CLI On Debian 11.3

Introduction:

In Linux, swap memory is used when physical memory is full. As swap memory is on a hard drive and relatively slow, it cannot be used instead of physical memory when it is inactive.

Procedure:

Step 1: Check the OS version by using the following command

root@linuxhelp:~# lsb_release -a
No LSB modules are available.
Distributor ID:	Debian
Description:	Debian GNU/Linux 11 (bullseye)
Release:	11
Codename:	bullseye

Step 2: List the disk by using the below command

root@linuxhelp:~# lsblk
NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda      8:0    0   60G  0 disk 
├─sda1   8:1    0   59G  0 part /
├─sda2   8:2    0    1K  0 part 
└─sda5   8:5    0  975M  0 part [SWAP]
sdb      8:16   0   10G  0 disk 
sr0     11:0    1  3.6G  0 rom

Step 3: Check the available swap memory by using the below command

root@linuxhelp:~# top
top - 21:40:09 up  1:41,  2 users,  load average: 0.62, 0.22, 0.12
Tasks: 278 total,   1 running, 277 sleeping,   0 stopped,   0 zombie
%Cpu(s):  1.0 us,  0.7 sy,  0.0 ni, 98.3 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
MiB Mem :   2920.1 total,    101.4 free,   1713.9 used,   1104.9 buff/cache
MiB Swap:    975.0 total,    974.0 free,      1.0 used.    957.1 avail Mem 

    PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND  
   1133 asterisk  20   0  757936  80180  38432 S   0.7   2.7   0:36.50 asterisk 
   1837 linuxhe+  20   0 3346964 189976  99628 S   0.7   6.4   0:08.89 gnome-s+ 
   2201 linuxhe+  20   0  400844  45448  35928 S   0.7   1.5   0:00.75 gnome-t+ 
    596 root      20   0  236416   9456   6216 S   0.3   0.3   0:10.11 vmtoolsd 
   3054 root      20   0       0      0      0 I   0.3   0.0   0:01.21 kworker+ 
   3241 root      20   0   10228   3960   3224 R   0.3   0.1   0:00.12 top      
      1 root      20   0  164188  10560   7824 S   0.0   0.4   0:02.67 systemd  
      2 root      20   0       0      0      0 S   0.0   0.0   0:00.01 kthreadd 
      3 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 rcu_gp   
     4 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 rcu_par+ 
      6 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kworker+ 
      8 root       0 -20       0      0      0 I   0.0   0.0   0:01.43 kworker+ 
      9 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 mm_perc+ 
     10 root      20   0       0      0      0 S   0.0   0.0   0:00.00 rcu_tas+

Step 4: Open fdisk to create partitions on /dev/sdb disk by using the below command

root@linuxhelp:~# sudo fdisk /dev/sdb
Welcome to fdisk (util-linux 2.36.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

Device does not contain a recognized partition table.
Created a new DOS disklabel with disk identifier 0x71a2e1a2.

Command (m for help): n
Partition type
   p   primary (0 primary, 0 extended, 4 free)
   e   extended (container for logical partitions)
Select (default p): p
Partition number (1-4, default 1): 
First sector (2048-20971519, default 2048): 
Last sector, +/-sectors or +/-size{K,M,G,T,P} (2048-20971519, default 20971519): +5G

Created a new partition 1 of type 'Linux' and of size 5 GiB.

Command (m for help): t
Selected partition 1
Hex code or alias (type L to list all): 82
Changed type of partition 'Linux' to 'Linux swap / Solaris'.

Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.

Step 5: Format the partition /dev/sdb1 to the swap file system by using the below command

root@linuxhelp:~# sudo mkswap /dev/sdb1
Setting up swapspace version 1, size = 5 GiB (5368705024 bytes)
no label, UUID=148cfbb0-c15e-450a-b32b-8477c3d10cd3

Step 6: Turn on the swap memory by using the below command

root@linuxhelp:~# sudo swapon /dev/sdb1

Step 7: Make fstab entry for swap partition by using the below command

root@linuxhelp:~# vi /etc/fstab
#/etc/fstab: static file system information.
#Use 'blkid' to print the universally unique identifier for a
#device; this may be used with UUID= as a more robust way to name devices
#that works even if disks are added and removed. See fstab(5).
#<file system> <mount point>   <type>  <options>       <dump>  <pass>
# / was on /dev/sda3 during installation
UUID=6183834d-0563-4576-a37d-b64b78a1640a /               ext4    errors=remount-ro 0       1
# /boot/efi was on /dev/sda2 during installation
UUID=BD43-BD7D  /boot/efi       vfat    umask=0077      0       1
 
/dev/sdb1  swap       swap    defaults     0 0

Step 8: Make permanent mounts of all entries in fstab by using the below command

root@linuxhelp:~# mount -a

Step 9: Check the swap memory by using the below command

root@linuxhelp:~# top
op - 21:46:36 up  1:47,  2 users,  load average: 0.21, 0.24, 0.16
Tasks: 279 total,   1 running, 278 sleeping,   0 stopped,   0 zombie
%Cpu(s):  0.3 us,  0.7 sy,  0.0 ni, 99.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
MiB Mem :   2920.1 total,    114.3 free,   1721.2 used,   1084.7 buff/cache
MiB Swap:   6095.0 total,   6093.7 free,      1.3 used.    952.0 avail Mem 

    PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND  
   1837 linuxhe+  20   0 3613264 189808  99364 S   1.0   6.3   0:12.48 gnome-s+ 
    596 root      20   0  236416   9456   6216 S   0.3   0.3   0:10.50 vmtoolsd 
    793 mysql     20   0 1298904 429036  33028 S   0.3  14.3   0:09.97 mysqld   
   1133 asterisk  20   0  757936  80152  38404 S   0.3   2.7   0:38.88 asterisk 
   2201 linuxhe+  20   0  401012  45436  35916 S   0.3   1.5   0:02.07 gnome-t+ 
   3279 root      20   0   10228   3908   3176 R   0.3   0.1   0:00.17 top      
      1 root      20   0  164028  10556   7824 S   0.0   0.4   0:02.69 systemd  
      2 root      20   0       0      0      0 S   0.0   0.0   0:00.01 kthreadd 
      3 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 rcu_gp   
      4 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 rcu_par+ 
      6 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kworker+ 
      8 root       0 -20       0      0      0 I   0.0   0.0   0:01.47 kworker+ 
      9 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 mm_perc+ 
     10 root      20   0       0      0      0 S   0.0   0.0   0:00.00 rcu_tas+

Step 10: Turn Off the swap memory by using the below command

root@linuxhelp:~#sudo swapoff /dev/sdb1

Step 11: Remove the fstab entries for /dev/sdb1 partition by using the below command

root@linuxhelp:~# vi /etc/fstab

Step 12: Delete the /dev/sdb1 partition by using fdisk by using the below command

root@linuxhelp:~# sudo fdisk /dev/sdb
Welcome to fdisk (util-linux 2.36.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Command (m for help): d
Selected partition 1
Partition 1 has been deleted.

Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.

Step 13: Check the swap memory by using the below command

root@linuxhelp:~# top
top - 21:48:11 up  1:49,  2 users,  load average: 0.20, 0.22, 0.15
Tasks: 279 total,   1 running, 278 sleeping,   0 stopped,   0 zombie
%Cpu(s):  0.0 us, 16.7 sy,  0.0 ni, 83.3 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
MiB Mem :   2920.1 total,    117.9 free,   1717.4 used,   1084.8 buff/cache
MiB Swap:    975.0 total,    973.8 free,      1.2 used.    955.8 avail Mem 

    PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND  
   3315 root      20   0   10228   3912   3176 R  11.8   0.1   0:00.03 top      
   1837 linuxhe+  20   0 3613248 189760  99364 S   5.9   6.3   0:13.80 gnome-s+ 
      1 root      20   0  164028  10556   7824 S   0.0   0.4   0:02.71 systemd  
      2 root      20   0       0      0      0 S   0.0   0.0   0:00.01 kthreadd 
      3 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 rcu_gp   
      4 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 rcu_par+ 
      6 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kworker+ 
      8 root       0 -20       0      0      0 I   0.0   0.0   0:01.49 kworker+ 
      9 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 mm_perc+ 
     10 root      20   0       0      0      0 S   0.0   0.0   0:00.00 rcu_tas+

Conclusion:

We have reached the end of this article. In this guide, we have walked you through the steps required to Create and remove swap memory in CLI on Debian 11.3. Your feedback is much welcome.

Tag : swap space Memory debian
FAQ
Q
What are the benefits of using Swap Memory?
A
The freed-up RAM can then be used to hold more programs that have a higher priority. It prevents RAM from running out of space. It acts as a backup for enhancing the actual space of RAM. It allows you to run heavy applications that require a large amount of RAM.
Q
What is the purpose of the swap?
A
The objective of a swap is to change one scheme of payments into another one of a different nature, which is more suitable to the needs or objectives of the parties, who could be retail clients, investors, or large companies.
Q
How to update the partition table?
A
Update the partition table by using "partx –a" command.
Q
What is the HEX code of Snap?
A
The hex code for SWAP is 82.
Q
How to view available swap memory?
A
To view available swap memory, use the command "swapon –s".