VSWAP, Is that on disk or in memory?
Is VSWAP on disk or in memory?
VSWAP is contained in memory, so VPS containers do not perform swap I/O functions to the harddrive. This means other customers who are swapping on the same node as your VPS are not impacting your servers performance.
So why is my VPS running so slowly?
VSWAP is made to emulate real swap, so the memory I/O to and from VSWAP is slowed down to emulate paging to and from a Harddrive.
So why not give us more memory and no swap?
OK, lets say you have a 3GB memory VPS with 1GB VSWAP.
If we gave you 4GB of RAM and no swap, as you use up all of your memory the VPS would not exhibit any issues right up to the point where it crashes due to memory exhaustion.
But with VSWAP, rather than crash, the system slows down as it starts to dip into swap use when memory is exhaused. This gives you an indication that something is wrong, and allows you to fix the issue, or purchase more RAM.
In reality, in the above scenario we have really provided you with 3GBs of RAM, and will temporarily loan you upto 1GB of RAM (that functions at hardisk speed). You have not paid for 4GBs of RAM.