virtual memory -vs- physical memory

[solharris]

Hello,

In the documentation for memory limiting, it says it is much better to limit based on Physical memory usage.

What is the point of limiting based on Virtual memory usage? When would anyone want to limit based on virtual memory instead of Physical memory? Can you give an example?

Im trying to determine if we should limit Virtual Memory at all, or if we should only limit Physical memory.

Thanks!

[iseletsk]

There is no reason to use Virtual Memory in CL6. It is there only because this is what we were able to provide initially -- and because it is the only memory limit we have in CL5. Right now, NPROC and physical memory limits are much better than virtual memory limits.

[henri]

Thanks Igor. I will disable VMem limits on our servers.

Out of curiosity... based on your experience with support cloudlinux on many different web servers for many different companies... what would you suggest is a good "default" value for NPROC?

[iseletsk]

100 -> basically think of it as a really good fork bomb protection. This is pretty much the only reason you need it --> so no one can create absurd number of processes.
So, 100 is good. 1000 would also be fine, but even with 100 99.99% of hosting clients will not hit this limit.