Proxmox/OpenVz memory issues
The clue to solve the problem can be in the 'throtling' word.
Check if Proxmox VM is OpenVz or KVM.
OpenVZ virtualisation is a bit different from your 'normal' servers or KVM's.
It looks like you are having memory problems on your Virtual Machines.
From the Proxmox web-console try increasing the memory allocated to the mail server. In servers that sometimes have problems with PHP or other services the memory usage sometimes 'peaks' and causes the OpenVZ containers to 'throtle' the memory usage. This can cause services to stop or crash on the containers.
I found that increasing the non-existant "swap" memory on the containers solved the issue on some of our problem servers.
Since OpenVZ uses filesystem level virtualisation there is no real "swap" memory on the containers anyway.
Last edited by SamTzu; 20th March 2010 at 23:06.