Swap files sizing

[Upendra Dhoble]

Hi,
we have physical server per bellow specs

1) two 8 core socket CPU
2) 256 or 128 GB ram
3) 2Tb x 8-10 SATA HDD

I am just trying to understand what will be the best size of swap file , if I want to run 50 VM at a time.
should I create a separate swap or leave to OS to define the size while doing the installation
welcome if any other suggestions for performance boost.

appreciate any help

Thanks
Upendra

 

[wolfgang]

Hi,

if you have to use swap this is never a performance boost.
Swap is a technique to prevent the Out of Memory killer to kill processes to make ram free.

 

[Upendra Dhoble]

I agree with you , however I am not sure in terms of proxmox configuration. does equal amount of RAM should be good ?

 

[wolfgang]

This was the old settings now we have max 8GB when you install PVE.
More than this makes no sense.
We ask the pve user and the most think the same.

 

[Rhinox]

...does equal amount of RAM should be good ?

There is nothing like "good" value for swap-size. It all depends on how much physical RAM you have, and how much RAM you plan to use (in this case, for host, caching, and all VMs)...

 

[Upendra Dhoble]

Thanks for reply, I will search for caching option which is new for me. however currently I am running 256 GB server having at least 40-50 VM running on it