What is VSwap?
Understanding VSwap memory management in OpenVZ virtualization.
Table of Contents
Understanding VSwap
VSwap is a memory management feature in OpenVZ that provides a more predictable and user-friendly memory allocation system compared to the traditional OpenVZ memory model.
Key Benefits of VSwap
- Simpler Memory Model - Uses familiar RAM + Swap concepts instead of complex parameters
- Better Performance - More predictable behavior under memory pressure
- Easier Configuration - Single parameter to configure instead of multiple memory limits
- Improved Stability - Reduces Out-of-Memory (OOM) killer issues
How VSwap Works
With VSwap enabled, your VPS has:
- RAM - Fast physical memory allocation
- VSwap - Virtual swap space (slower than RAM, but prevents OOM errors)
When your VPS uses more memory than the allocated RAM, the system automatically moves less-used data to VSwap, similar to how traditional swap works on physical servers.
Traditional vs VSwap Memory
Traditional OpenVZ (Old)
- Multiple complex parameters (privvmpages, kmemsize, etc.)
- Difficult to understand and configure
- Unpredictable behavior under memory pressure
VSwap (Modern)
- Simple RAM + Swap model
- Easy to understand (just like physical servers)
- Predictable performance characteristics
Checking VSwap on Your VPS
You can check your VSwap allocation with:
free -mThis will show your RAM and swap allocation.
Learn More
For detailed technical information about VSwap, please see the official OpenVZ documentation: http://wiki.openvz.org/VSwap
Note
All RamNode OpenVZ VPS plans use VSwap for better performance and stability. You don't need to enable or configure anything - it's automatic.