64bit builds



I setup a new win03 64bit box. Specifically because sql reports rendered
locally with the asp.net 2.0 report viewer control would crash because of
memory problems in the worker process (very important).

Anyway we normally deploy from a 32 bit development machine to the server
using a command like:

aspnet_compiler -v %virtualPath% -p %sourcePath% -f %destinationPath% -c

After reading a slew of kb articles I am still at a loss on how to compile
the application and how to setup IIS.

I don't see a command line switch for x64.

The issues on IIS are:
On 64-bit Windows, the World Wide Web Publishing service does not support
running 32-bit and 64-bit worker processes concurrently on the same server.


Do I need to configure the server to run 32 bit?
Do I need to specify what .net DLL is allowed in the IIS web service
extensions tab of the admin tool.
How do I configure IIS.

Steven Cheng[MSFT]

Hi Chuck,

From your description, you want to deploy an ASP.NET 2.0 application
developed on a 32 bit machine to a 64 bit server, correct?

Based on my experience, since 64 bit windows server only support running
one version(32 bit or 64 bit) of the ASP.NET 2.0 application at a time, so
you need to consider whether to compile and run your ASP.NET application as
32 bit or 64 bit. You have the following options:

1. Still develop the ASP.NET application and precompile it(if necessary) on
32 bit development machine, however, when you deploy it onto the 64 bit
server, you need to configure the IIS server to running as 32bit (wow) mode:

#How to switch between the 32-bit versions of ASP.NET 1.1 and the 64-bit
version of ASP.NET 2.0 on a 64-bit version of Windows

However, as you found, you can not run both 32 bit and 64 bit ASP.NET
application in IIS6 the same time.

2. Another option is you build your ASP.NET 2.0 Web application that
naturally target x64 net framework 2.0, however, since .net framework 2.0
(x64) version can only be installed on 64 bit system, you need to
build/precompile your ASP.NET 2.0 web site project on 64 bit system with
.net framework 2.0(x64) sdk(or visual studio 2005) thus, the compiled
applciation can naturally running on x64 system without configure IIS to
running in 32 bit mode.


Steven Cheng

Microsoft MSDN Online Support Lead


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Thanks Steven,

Our only reason for setting up the 64bit box was so that the SQL
ReportViewer control would quit crashing the IIS worker process on exports.

If we configure to run as 32 bit, would IIS be running a 32 bit worker
process and would we have the same worker process memory limitations?

"IIS only supports 32-bit worker processes in Worker Process Isolation mode
on 64-bit Windows."

From my readings: "On 64-bit Windows, the World Wide Web Publishing service
can run 32-bit and 64-bit worker processes. Other IIS services like the IIS
Admin service, the SMTP service, the NNTP service, and the FTP service run
64-bit processes only".

Does that mean I couldn't use the IIS Admin or SMTP service, if I am running
32 bit.


IIS 6.0 runs in one of two distinct modes of operation, which are called
application isolation modes: worker process isolation mode, and IIS 5.0
isolation mode which is almost identical to the process model of IIS 5.1 and

IIS only supports 32-bit worker processes in Worker Process Isolation mode
on 64-bit Windows.

If I run .net in 32 bit and iis in the 5.o mode will I get a 64 bit worker

Steven Cheng[MSFT]

Thanks for your reply Chuck,

When you configure the IIS6 worker process to run in 32-bit mode, it only
affect those service that use the WWW worker process (w3wp.exe for IIS6 in
worker process isolation mode). And for FTP, SMTP ... services, they're not
part of the WWW service, the 32 bit switch won't apply for them. In other
words, your swtich for WWW services won't affect any other services that do
not use w3wp.exe worker process.

And as for your following question:
If I run .net in 32 bit and iis in the 5.o mode will I get a 64 bit worker

No, run IIS under iis5 compatible isolation model won't help. In such mode,
no 32 bit web application can be run in IIS6, just like you keep the
default 64 bit mode (IIS6 worker process isolation model).

So the limitation here is:

** if the ASP.NET application is compiled against 32bit .net framework, it
can only run in 32 bit IIS worker process, if the server is 64 bit, you
should either configure IIS6 to run under 32 bit worker process mode or
recompile the application through 64 bit .net framework.


Steven Cheng

Microsoft MSDN Online Support Lead

This posting is provided "AS IS" with no warranties, and confers no rights.

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