This is kind of an angry post – apologies beforehand!

For some stupid reason, Windows Server 2008 (not the R2 version by the way) and Windows Server 2008 for Small Business has the ‘hibernate’ feature turned on by default. Hibernation is when a machine commits all running memory to disk and powers down only to pull this data back off the disk upon powering on and thus giving you the impression everything is as it was before you ‘hibernated’ the machine – I say ‘impression’ as very often it doesn’t work properly.

Anyway, as it commits all running memory to the disk, the hibernation system has to create a file which is usually equal in size to the installed physical memory (RAM) of the machine. Now in a PC, that might not be much, but in a server, that could be a phenomenal amount of storage. So let’s say you’re running a server with a 140GB partition and 16GB of RAM and over time your server consumes 100GB of data from users. As an administrator you look at the server and see only 8GB of free space and start to wonder what happened the other 32GB? Well remember the 16GB of RAM you have installed? 16GB of hard disk space has been consumed by this stupid hibernation system – a feature I cannot see any server ever needing or using. OK, so now you’ve accounted for 16GB of your 32GB missing storage – the rest is probably your pagefile if you set it to be huge or system managed (that’s your call to fix!)

So you need your 16GB back right? OK, well then you need to disable hibernation. Before Windows Vista you’d go into the power options and turn it off there. But thanks to the foresight of Microsoft in introducing Windows Vista, all is not as it was. The way you do it now is via a command. Here’s how:

1. Click Start, and then type cmd in the Start Search box.
2. In the search results list, right-click Command Prompt, and then click Run as Administrator.
3. When you are prompted by User Account Control, click Continue.
4. At the command prompt, type powercfg.exe /hibernate off, and then press ENTER.
5. Type exit, and then press ENTER.

So go forth an take back your server’s storage. It might get you out of that tight spot!

(Thanks goes to VMPros.nl for the instructions)