Basic Guidance on Swap Space Sizing on Redhat

       Swap space or a swap area is space on the disk drive used as overflow for parts of memory that are not currently being used. This allows the system to make room in main memory fr data currently beginning processed, and provides emergency overflow if the system is at risk of running out of space in main memory.

SYSTEM RAM and Recommended Minimum Swap Space

Up to 4 GB            : at least 2 GB

4 GB - 16 GB         : at least 4 GB

16 GB –  64 GB    : at least 8 GB

64 GB – 256 GB   :  at least 16 GB

Creating and Using an Additional Swap Partition

- Create a new partition using fdisk . Additionally, change the partition type to “ 0*82 Linux Swap” before saving changes with fdisk.

- mkswap /dev/vdaN  will prepare the partition for use as a swap area.

- blkid  /dev/vdan will determine the UUID.

-  Add the new swap space to /etc/fstab :

 UUID-uuid         swap     swap    defaults              0             0

- swapon –a will activate the new swap area.

- swapon –s  will show status of current swap areas.

- swapoff  /dev/vdaN  will de-activate that particular swap area.