ksmtuned service fine-tunes the kernel same-page merging (KSM) configuration by looping and adjusting
ksm. In addition, the
ksmtuned service is notified by libvirt when a guest virtual machine is created or destroyed. The
ksmtuned service has no options.
# systemctl start ksmtuned
Starting ksmtuned: [ OK ]
ksmtuned service can be tuned with the
retune parameter, which instructs
ksmtuned to run tuning functions manually.
/etc/ksmtuned.conf file is the configuration file for the
ksmtuned service. The file output below is the default
# Configuration file for ksmtuned.
# How long ksmtuned should sleep between tuning adjustments
# Millisecond sleep between ksm scans for 16Gb server.
# Smaller servers sleep more, bigger sleep less.
# KSM_NPAGES_BOOST - is added to the `npages` value, when `free memory` is less than `thres`.
# KSM_NPAGES_DECAY - is the value given is subtracted to the `npages` value, when `free memory` is greater than `thres`.
# KSM_NPAGES_MIN - is the lower limit for the `npages` value.
# KSM_NPAGES_MAX - is the upper limit for the `npages` value.
# KSM_THRES_COEF - is the RAM percentage to be calculated in parameter `thres`.
# KSM_THRES_CONST - If this is a low memory system, and the `thres` value is less than `KSM_THRES_CONST`, then reset `thres` value to `KSM_THRES_CONST` value.
# uncomment the following to enable ksmtuned debug information
npages sets how many pages
ksm will scan before the
ksmd daemon becomes inactive. This value will also be set in the
KSM_THRES_CONST value represents the amount of available memory used as a threshold to activate
ksmd is activated if either of the following occurs:
The amount of free memory drops below the threshold, set in
The amount of committed memory plus the threshold,
KSM_THRES_CONST, exceeds the total amount of memory.