John, the recommended value is listed at the bottom of the Virtual Memory
form. It is 1.5x physical memory + 2MB.
However, with 2GB RAM, depending on what you are doing, having a pagefile
this size can be just a waste of space. I have sought clarification on what
the optimal pagefile size with larger memory configs but it seems to depened
mostly on what you use the system for. ON small memory systems, the 1.5x
rule stands - if it is smaller, then you run the risk of Out of Memory
errors, if the page file is much larger then to be able to use it, memory
has to be grossly oversubscribed and performance will be suffering very
badly already.
If you install SP2 you will also notice that there is a new option of No
Paging File.
If you can afford the disc space then use the recommended settings. If you
wish to experiment with the new No Paging File option then OK, but be aware
that you may start to see Out of Memory errors when the full 2GB is in use.
If you need to economise for disk space reasons then you can trim the size
down somewhat (EG 1GB), however don't do this if you are running server
systems such as multi-user databases, email servers, and so on as you may
strike major performance issues if the memory allocations in these systems
is not under the total VM size.
For best VM performance, the page files can be split across multiple drives
and controllers. However to do this effectively one needs to understand
first the IO usage patterns of the *disc drives* concerned. If you had say 2
IDE disc drives on master and slave, then there is absolutely no point in
splitting the page file (there can be no overlapped IO with IDE or SATA,
there can be with SATA RAID, and it is normal for SCSI). It is completely
pointless splitting a pagefile across partitions on the same drive (unless
you are out of disc space).
Lastly, the pagefile should be large enough for a memory dump should your
system be or become unstable. Without an adequate sized page file, you will
not be able to have a full PM dump or do a PM analysis. (most people don't
know what to do with one anyway, so this is rather moot).
- Tim
