How can I fix disk space issues on SBS 2008 ?

Do you get warning emails like this from your SBS 2008 server and wonder where all the disk space has gone too?  Well there are a few places you can look for the missing disk space.

Subject: Windows Small Business Server 2008: Critical Event Notification

An alert was detected on your network. Further investigation into the issue is recommended.

Computer: SBS2008SVR

Date/Time generated: 25/03/2010 11:33:34 AM

Title: Percent Free Disk Space

Source: Performance Threshold

Description:

The free disk space on this computer has dropped below its notification for low disk space threshold.

Volume Name: C:

Free Space: 8530649088

Volume Size: 85895147520

Troubleshooting suggestions:

1) If the issue is being reported on the server running Windows SBS, consider freeing up the disk space by reconfiguring its disk using the storage tasks available under the “Backup and Storage” tab in the Windows SBS Console.

2) If the issue is being reported on a client computer, consider freeing up the disk space by using the Disk Cleanup and removing any unnecessary files on the computer.

Firstly – you want to check out and be sure where the disk space is being used.  To do that I use a tool called TreeSize Free which you can download from the vendor. 

When you run the tool, make sure you run as administrator or you will be blocked from seeing the true story of your disk utilisation.  You can see below the screenshot of the server that generated the problem above. We are currently using over 64GB of the servers 80GB C: drive.  You will notice that the INETPUB folder is over 15GB of that space, and the Windows folder is nearly 25GB.

If we expand the Windows folder some more you will see that there is 2.5GB of space used in the c:\windows\system32\CertLog folder.  This folder is where the Certificate Services database resides.  Each time Windows Backup is run, it will automatically create and additional log file of 1MB in size.  Now that does not seem like a lot, but in my case there’s 2500 of them totalling 2.5GB.

If we take a look in the c:\Inetpub folder we can see the logfiles folder has one very large folder with 14.6GB used.  That is actually the log folder for the WSUS IIS website and it’s logging every time your workstations check in with it.

To clean up the IIS logs is pretty simple as we can run a script to delete all the log files from the c:\inetpub\logs\logfile directory.  If you don’t want to keep logging running on the WSUS website, you can disable it.  To disable it use the following procedure;

1. Logon to the SBS 2008 server using your SBS Administrator account
2. Click Start > All Programs > Administrative Tools > Internet Information Services (IIS) Manager
3. Expand your server name
4. Expand the Sites Node
5. Select the WSUS Administration Node
6. In the middle pan, double click on the the Logging option under the IIS group. 
7. You will then be able to select Disable from the Actions menu in the right hand pane to disable Logging altogether.

Note that if you disable logging on the WSUS Administration site, you will no longer be able to use those logs to help diagnose any issues related to your client computers getting their patches from the SBS 2008 WSUS server.

Cleaning up the Certificate Services logs is however a little harder.  We need to stop the Active Directory Certificate Services first and then delete all the files in that specific folder EXCEPT our Certificate Services database.  The filename of the certificate services database will be different on each server as it’s made up of the server name and the domain name.  Mine was called smallfamily-SBSFAQSVR1-CA.edb.

Fortunately – I’ve created a script that you can use to periodically clear out these log files.  You can download it here and use the Task Scheduler to schedule it to run on a weekly basis if you like.

After running the script you can see that we’ve cleared up quite a bit of disk space on the server.