Swap Memory: When & How To Use It On Production VMs

Tue, 02 May 2023 00:00:00 +0000

Swap memory, also known as virtual memory, is a space on a hard disk that is used to supplement the physical memory (RAM) of a computer. The swap space is used when the system runs out of physical memory, and it moves less frequently accessed data from RAM to the hard disk, freeing up space in RAM for more frequently accessed data. But should swap memory be enabled on production systems and cloud-provided virtual machines (VMs)? Let’s explore the pros and cons.

Monitor KSM performance with Netdata

Tue, 01 Nov 2022 00:00:00 +0000

Monitoring KSM (Kernel Same-page Merging) performance at deduping memory shared across VMs.

Kernel Same-page Merging (KSM)

Linux kernels store memory in pages which are moved in and out of memory as a single block. On most Linux architectures pages are 4096 bytes. KSM (Kernel Same-page Merging) is a kernel feature that scans memory looking for pages with identical content, and then de-duplicates them. The most common use-case where such duplicate pages occur is on hosts running multiple virtual machines (VMs).

Vm on Netdata

Swap Memory: When & How To Use It On Production VMs

Monitor KSM performance with Netdata

Kernel Same-page Merging (KSM)