Scaling with ASP and Server Memory Issues

[greg]

Hi,

I am hosting hundreds of websites on a webserver using a combination of sql
and asp.
SQL is on a different server. The web server is running win 2003 iis 6 with
a single processor and 1 GB Ram. All websites are in 1 app pool.

I find that i get out of memory errors or no new sessions are created when
the virtual bytes for an App pool starts to breach over 1500mb. So i recycle
the App pool at a limit of 1500mb.

This leads to the app pool recycling 1-2 times a day.
Typically the Private Bytes counter is saying 293mb and virtual bytes is
1438mb.
I don't know whether this is a leak somewhere in ASP or normal with IIS but
the virtual bytes only seems to increase over time and not stablise or go
down as i would expect when users visit and leave a website.

I have a script that i use to let uses download files from the server. It
uses the response.binarywrite method. If i download a large files (i.e. over
100mb) then i see a big jump in the virtual bytes that IIS allocates in the
w3wp.exe process. This does not appear to go down after the file has been
downloaded although Private Bytes goes up and then down initially. I was
thinking that this may be a cause of the problem?!

....or maybe it is typical for these types of large scale ASP applications?
Would increasing the main memory RAM to 2GB help in this situation. The main
Physical Memory still reports about 300mb free when i get the memory
problems?

Would it help to split the websites into a couple of different App Pools,
then increase the page file size to something larger and hence each App pool
gets to use a separate 2GB memory space? Would i benefit from moving to
Windows 64bit edition and installing more Ram and having a large Page file
to cope with the large Virtual Bytes?

Can anyone offer some guidance who have had similar issues with hosting
their sites?

Help much appreciated.