While using Linux/Unix OS, there are various configurations that may be changed to optimize the availability of resources to Fiorano. Below sections discuss the various configuration options.
To change maximum processes per user
- open /etc/security/limits.conf as root user
Write the following lines at the bottom of the page.
- Restart the machine.
To change maximum file handles per user
- open /etc/security/limits.conf as root user
Write the following lines at the bottom of the page.
- Restart the machine.
Checking the Swap Size
# free -k
The command free
is used to know how much swap space is currently used by the system. It displays the memory details in KB.
Following is a sample output resulting from free -k
command:
# swapon -s
Swapon command with option -s displays the current swap size in KB and the file name.
Following is a sample output resulting from swapon -s
command:
# cat /proc/swaps
This command is same as the swapon -s
command, which gives the same output:
Increasing the swap size
Additional Swap Space can be created using a:
- Hard Drive
- File
Both the methods are explained in the below sections.
Using a Hard Drive Partition
If you have an additional hard disk (or space available in an existing disk), create a partition using fdisk
command.
Assume that the partition created is: /dev/sdc1 and perform the following actions:
Setup this newly created partition as swap area using the
mkswap
command:# mkswap /dev/sdc1
Enable the swap partition for usage using
swapon
command:# swapon /dev/sdc1
Add the following line to the /etc/fstab file to make the swap space partition available even after the reboot:
# cat /etc/fstab
Verify whether the newly created swap area is available for your requirement using
swapon
andfree
commands:# swapon -s
Sample Output for # swapon -s command# free -k
Sample Output for # free -k command
Using a File
If you do not have any additional disks, create a file somewhere on your file system and use that file for swap space.
Create a swap file with the name "myswapfile" under /root directory with a size of 1024MB (1GB) using the following
dd
command:# dd if=/dev/zero of=/root/myswapfile bs=1M count=1024
Check the user permissions set in the file using the following command:
# ls -l /root/myswapfile
- Create Root Permission, that is, change the permission of the swap file so that only root can access it.
# chmod 600 /root/myswapfile
Make this file as a swap file using
mkswap
command:# mkswap /root/myswapfile
mkswap command output- Enable the newly created swapfile.
# swapon /root/myswapfile
To make this swap file available as a swap area even after the reboot, add the following line to the /etc/fstab file using command:
# cat /etc/fstab
Verify whether the newly created swap area is available for your requirement using
swapon
andfree
commands:# swapon -s
Sample Output for # swapon -s command# free -k
Sample Output for # free -k command