New Member, first Questions

[rethus]

Hi @ all,

i'm a newb on Proxmox VE and have some questions. Hope someone can answer me.

For example i try to create some virtual-machines on an PC with 8 GB RAM. What is the best way to do this with proxmox?

Can i addign all of the RAM to the VMs or should i take a rest for flexible RAM?
For Example my 8GB.. can i assign 512MB to 16 VMs? Or should i left 1GB which is devide to useres who need a little more than 512 for short time (Flexible RAM)?

Are there some Toturials which help me for startup and give hints for a good configuration which included some experiance data? (Maybe in German-Language)

Thanks a lot for your answers.

 

[yatesco]

It depends If you think all the VMs will each use all of its allocated memory then no, you shouldn't. However, most virtual machines are under utilised, i.e. VM1 has 1GB but actually most of the time it is only using 400MBs of RAM. If that is the case you could assign 12 or ever 16 VMs in 8GB.

This is referred to as 'over-comitting memory', or rather it is this characteristic that allows over-committing memory to be viable. Be warned though, if those VMs do suddenly need all their memory then very bad things will happen.

It does make a difference if you are using KVM or containers though - if they are non-java based Linux machines then use an OpenVZ container, otherwise use KVM. Containers are much more efficient in this regard. I am not saying KVM is slow by any means, but it is more of a black box to the host OS (I think).

The best thing to do is play around and experiment.

 

[tom]

if you run a lot of similar KVM guests you should use KSM.

on a test server with 8 GB of ram I easily managed to start 30 windows XP guest with 1 GB ram each without problems. but I just installed them only for testing and run them with no load on each VM.

but anyways, KSM is cool.