Recommendation for free memory for a node

[Deleted member 93625]

Hi there,

Just wondering how much free memory should be kept for a node. Do you have a specific figure for this, for example, it is recommended not to use more than 90% of host RAM? I believe there should be some RAM left for some VM operations e.g. live migration, HA?

I haven't tested this but what's happening when a node having low memory? Does it just crash and reboot or something else? Thanks.

Eoin

 

[narrateourale]

I haven't tested this but what's happening when a node having low memory? Does it just crash and reboot or something else?

The OOM killer will become active and kill a process, usually a VM as they a good targets with their high RAM usage

Though you might have other mechanisms that can free up RAM to some degree. ZFD for example might use quite a bit of RAM for caching but will free it when needed.