Again, that is why i am asking how to reproduce the bahaviour. If 5 people have serious performance problems, it should be possible that one of you find a way to reproduce the behaviour?
I can't fix something that works for me.
Good point Dietmar,
However I would like to clarify a couple of points. We have that issue on a production server that only runs OpenVZ and no KVM. We have not noticed any IO issue at all as we run Adaptec Raid with 512MB which at no load gives us between 500 - 600 MB/s bandwidth. Our issue is clearly caused by many processes which seem to be more mysql that spike every now and then. The only issue we have seem to be this load spike problems. Our IO delays is usually 0.05% rarely goes up.
So it is possible that something is not managing the processes very well or so.
In order to reproduce this issue I think you would need to setup a test environment with 10 OpenVZ vps that are live and get traffic. Maybe it is time to create such a benchmark environment. You can install some templates like wordpress, sugarcrm etc that use databases and run some queries that would heavily use database as well as hit the VPS with traffic (maybe use the ab tool to call a page that makes an intensive database call) . This is in my view the proper way to emulate a production environment.
We are at the verge of losing customers because of these spikes that slow down all the other VPSs and until you can really build load testing environments you might never get proxmox to be seriously considered again to use in production environments but a lot of traffic.
I am extremely frustrated right now because it is not even easy to migrate some VPS to another host. Some of our users pointed their domains to their IPs. a few days ago I was trying to migrate a couple of VPSs to the previous host so I could test there instead of testing on a production server entirely but it was not picking up the IPs. Although that host has the proper values for vmbr0.0 and vmbr0.1 which has the IP ranges of the VPS.
This was very frustrating that two proxmox servers cannot pickup the IPs properly. Now if I migrate a VPS to the other host I have to change its IP to put it in a range that would be defined only on the other host and not on the main one. I rebooted that old host many times, it comes online, the interface settings are right but you cannot ping the VPS.
Let me know your thoughts.
I wonder if we should just go back to straight OpenVZ...