MSR Consulting TechnoBlog

USB Drive Errors When Disconnecting From SBS 2003

May 17th, 2006

There have been recent reports regarding problems when using USB drives as backup devices on Microsoft Small Business Server 2003 if you frequently disconnect them for things like offsite rotation or other similar activities.

Symptoms include error messages from the server regarding “No Disk Space Remaining” when you unplug the drive so as to connect another one.  Various SBS user group members have reported having a problem with USB drives where the server would simply lock up as well.  I currently do not have any information in regards to Service Pack levels, etc. that are effected.  I have to assume that the issue still exists with the latest Service Packs and patches as of 5/15/06 otherwise Microsoft PSS would have advised the effected customers to simply apply a released update.

The best way to avoid these errors is to stop the device from the task tray prior to disconnected it from the server port.  This obviously requires logging on to the server however and depending upon your processes that may not be feasible for you. You could attempt to use a scheduled job and a utility for executing a USB Stop command, but I have no information currently as to whether this will resolve the issue in 100% of cases.  Hopefully one of our faithful readers will have more information as Microsoft is currently not very forthcoming to my inquiries. 

The reported fix at the moment  came from a Microsoft customer making a call to Microsoft’s PSS group – albeit not one that they have included in any public knowledge base articles as yet.

As always, whenever I hear of one of these mysterious fixes that isn’t made publicly available I’ll attempt to get it posted.  That said, there are usually good reasons that Microsoft doesn’t post these types of fixes publicly.  They aren’t always fully tested so they haven’t been through the complete quality control process, and applying one of these fixes can be extremely risky if you don’t know exactly what you’re doing.

So with all due warning, I provide this information:

The issue is related to the ”USB device selective suspend” structure.

You’ll need to open up your registry editor and under the HKEY_LOCAL_MACHINESystemCCSServicesusb section create a DWORD key called “DisableSelectiveSuspend”

Give it a value of “1” to disable selective suspend.

It goes without saying that you should backup your registry and this key specifically before making this modification.

 Matt Ridings

MSR Consulting

Entry Filed under: Small Business Server, Consulting