Memory Swap Ratio Company System
Today, a monitoring system indicated that one of the systems in the company has run out of memory. Executing
htop on this system indicated that the
Memory was nearly full
(~8GB) even as the
Swap Space (~0.5GB).
Stopping some of the services decreased the
Memory use, but the
Swap Space remained fully allocated.
According to this documentation it seems that the
Swap Space of this Company's system does not match the recommended space:
S = M < 2 ? M * 2 : M + 2
Default Swap Space Test System
htop on a test system results in:
which means a ratio of
Subquestion: Why does the default
Swap Memory Space Ratio not equal
Clear and Increase Swap Space on a running system
Increase Swap Space
This documentation indicates that several commands should be executed in order to increase the Swap Space. Are all these commands really required?
Clear Swap Space
According to this documentation the Swap Space could be cleared by executing:
swapoff -a && swapon -a
Safely increase Swap Space
This documentation recommends to create a backup before increasing the Swap Space, but it does not indicate the possible impact. As this concerns a production system it is important to know if it is safe to increase the Swap Space on the system while it runs or e.g. should a new system be created and the date subsequently be moved?
What is the fastest and safest way to increase the Swap Space on Scientific Linux?