VSwap or Virtual Swap in OpenVZ is a memory management model introduced for better performance. This model uses a swap-based approach as compared to the older User Beancounters (UBC) model. With VSwap, when a container’s physical memory limit is reached, a certain amount of swap memory is allowed on top of it, creating a more consistent performance behavior. This helps prevent applications from being killed due to out of memory errors and instead allows applications to slow down. This technology makes memory management more efficient and reduces the risk of unforeseen issues regarding high memory use.
