Important quote:
As xemul said.. the VE has no concept of the difference between ram and swap. Its just "memory" at the VE level. So, your HN can have 64MB of ram and 64GB of swap. Or, your HN can have 64GB of ram and 64MB of swap. In the VE, the privvm, oomguar, vmguar are uneffected by this. Only the performance changes between the two scenarios. In either case, you can guarantee and limit each VE to an arbitrary amount of memory. This drastically differs from the conventional mem management of vmware/xen (isoloation). VZ is a shared kernel model and no resources are "hard dedicated" or "hard assigned".
- not possible to give/assign/guarantee a VE XX swap and YY physical memory - not possible to restrict a VE from using physical memory and use swap instead
Think of the VZ virtual servers like resource containers, not individual linux boxes- VZ is a shared kernel approach to virtualization.
Hope this clears it up for you.
Rick Blundell
Check memory usage in OpenVZ
# vzmemcheck -vA
To see the usage of memory by a VPS container, check the following file:
# cat /proc/user_beancounters
More info at: http://wiki.openvz.org/Proc/user_beancounters
References
- Memory & SWAP. URL: http://forum.openvz.org/index.php?t=msg&goto=9834&
About OpenVZ Memory Management