Update: The original question was for Windows Server 2008, but the solution is easier for Windows Server 2008 R2 and Windows Server 2012 (and Windows 7 and 8). You can add the user through the NTFS UI by typing it in directly. The name is in the format of IIS APPPOOL\{app pool name}. For example: IIS APPPOOL\DefaultAppPool.
IIS APPPOOL\{app pool name}
Note: Per comments below, there are two things to be aware of:
- Enter the string directly into the "Select User or Group" and not in the search field.
- In a domain environment you need to set the Location to your local computer first.
Reference to Microsoft Docs article: Application Pool Identities > Securing Resources
Original response: (for Windows Server 2008) This is a great feature, but as you mentioned it's not fully implemented yet. You can add the app pool identity from the command prompt with something like icacls, then you can manage it from the GUI. For example, run something like this from the command prompt:
icacls c:\inetpub\wwwroot /grant "IIS APPPOOL\DefaultAppPool":(OI)(CI)(RX)
Then, in Windows Explorer, go to the wwwroot folder and edit the security permissions. You will see what looks like a group (the group icon) called DefaultAppPool. You can now edit the permissions.
However, you don't need to use this at all. It's a bonus that you can use if you want. You can use the old way of creating a custom user per app pool and assigning the custom user to disk. That has full UI support.
This SID injection method is nice because it allows you to use a single user but fully isolate each site from each other without having to create unique users for each app pool. Pretty impressive, and it will be even better with UI support.
Note: If you are unable to find the application pool user, check to see if the Windows service called Application Host Helper Service is running. It's the service that maps application pool users to Windows accounts.
Type appcmd list apppool, and use exactly what it lists there in your appcmd start apppool /apppool.name:
Names with spaces should be escaped with double quotes. For example:
%SYSTEMROOT%\System32\inetsrv\appcmd stop apppool /apppool.name:"My App Services"
Post the exact command you're trying to run ; perhaps you missed the colon or there's another problem with the syntax?
Edit - you're adding a space between the colon and the first double-quote. Remove that space, use the double-quote, and see what happens.
Best Answer
An app pool just serving up static content is less than 5Mb. Once you add the .NET framework then it will jump to over 10MB (it really varies on what is loaded). After that it's up to your application as to what it uses.
If you're wondering how much app pool overhead there is to put sites in their own app pools, it's really not much. There is the small bit of app pool overhead, and it does mean that your programming framework (i.e. asp.net) may have duplicate assemblies loaded into memory. That means that there may be as much as 15-20MB overhead per additional app pool. With memory so cheap, it's often worth it, although it can add up if you have a ton of sites.