If you’re going to look for memory leaks, you need Performance Monitor (perfmon).

Here is a method you can use to detect memory leaks:

First open Perfmon and select the .NET CLR Memory Performance object and the counter # Bytes in all Heaps for all your w3wp instances (w3wp#1, w3wp#2, etc).

With these counters you will be able to see if any w3wp process is accumulating memory. Leave this running for some hours and you will notice rapidly.

Now once you have determined a w3wp process that is leaking, you need to clearly identify it. Of course the w3wp#1 notation, isn’t helping here. So you need to find out what does it correspond to. In my previous post, I already mentionned that you can find out the Web Application if you have the Process ID. Clearly, in this case, we still need to find the process ID.

I have come across 2 methods for this:

1. You can set a registry key on your server(s) that will translate the w3wp#1 into w3wp_pid. See KB281884 for this (I hate setting registry keys if it can also be done without [:D] )

2. You can also find out this information using perfmon! Add the Performance object Process with the counter ID Process and for the instance of w3wp#… for which you want to know the pid. And voila, you get the Pid. 

Now, using cscript iisapp.vbs you can find out the Web application that is leaking. With this information you can then check which solutions are deployed to this web application and you can already start with the fingerpointing [6] !

I want to thank my good friend and colleague Cedric Carrette for sharing this information with me.

Looking at the processes of one of my servers, I notices a huge memory consumption on one of the w3wp.exe’s running on the Moss server. Immediately I wanted to find out which SharePoint Webapp is causing this. And there I was….. Well you need to know the Process ID first (View -> Select Columns… in Task Manager) and then you can use the iisapp.vbs tool that comes with IIS. 
I found this information on the this post from the Thoughts about IIS (and now SharePoint blog) which describes the following: 
During the course of working through issues, I get asked at least twice a week how to determine which application pool maps to a particular worker process PID (Process ID) on a server.  I suppose there are lots of ways to determine this, but here two that come to mind to determine the answer. 
The first way, and by far the easiest, is to use one of the new scripts that come in the box called IISAPP.VBS.  It is located in the %SystemRoot%\system32 directory.  For example: 

As you can see, this script makes it very easy to determine what the PID is of each specific Application Pool.  This is nice to use when trying to determine which PID you may want to snap a dump of for debugging purposes.

Today, I had to create a site template of a specific site and create a new site based on that template on the same server and the same web application. Everything went ok creating the site template and creating the new site. However when I wanted to apply a the same theme to the site as the source site, I got the following error message:

A theme with the name “Citrus 1011″ and version already exists on the server.

Crap, what the f*** !

Luckily for me, one of my colleagues, Jonathan Martiat, had encountered this before and also rememered the solution.If you encounter this error then do the following:

1. Open the website in SharePoint Designer and delete the _themes folder completely.
2. execute an iisreset on your frontend server(s)
3. reapply the necessary site theme

….and that’s it !

I must admit, that I had tried to do it without executing an iisreset and although I did still get the error message, the site theme was indeed applied, but doing it after iisreset, completely wipes out the error message

So, thanks Jonathan for the good tip and hopefully you guys also benefit from this post.