Low Disk Space on Windows Server 2008 R2

by Andy, Updated on: February 28, 2020

Windows Server 2008 has been released for such a long time, but it is still a widely used Operating System. The same with previous Server 2003, when system C drive is running low on disk space, Windows Server 2008 pops up "Low Disk Space" warning from bottom right taskbar. This is the most common issue on all Windows versions and it is a headache for many people. In this article I'll show you how to fix low disk space issue on Windows Server 2008 and R2 with ease.

About Server 2008 Low Disk Space Alert/Warning

If system C drive is running out of space, or even no free space in C drive, it causes many problem such as: no space to install Windows Updates and applications, server runs much slower, stuck or even crash. To alert people to fix this issue as fast as possible, Microsoft creates such Low Disk Space balloon alert on Windows Server 2008 (R2).

Low disk space 2008

From Microsoft's explanation, users will receive Low Disk Space warning in following situations:

  1. When free space reaches 200MB
    Users receive the warning message for 10 seconds, once per session. In this situation, system automatically takes actions to maintain minimum performance capabilities.
  2. When free space reaches 80MB
    Users receive the warning message for 30 seconds, every four hours, twice per session. In this situation, Windows starts to free up drive space by deleting previous System Restore points.
  3. When free space reaches 50MB
    Users receive the alert message for 30 seconds, every five minutes, until the free space is above 50 MB. In this situation, Windows will purge the all System Restore points, and suspend the System Restore function. System Restore will not be reactivated until 200MB free space available in the system partition.

When you see the low disk space alert/warning on Windows 2008 server, you'd better fix this issue as fast as possible.

How to fix low disk space issue on Windows Server 2008 (R2)

Firstly, you'd better clean up disk. There are many kinds of junk files in system partition C, you can reclaim disk space after deleting these junk files. It is important to get some precious free space in a short time. So, your server could keep running in the right way, also, there's space to install some programs to help solve this problem.

Secondly, you'd better add more free space to C drive from other data partitions. In general, you won't reclaim over 10GB free space. If you don't give more to C drive, the low disk space warning message will pop up in the near future, because these free space will be eaten up quickly by new generated junk files.

Clean up disk to reclaim space

To delete junk files and reclaim disk space, Windows Server 2008 has a native Disk Cleanup utility, which is able to remove most of junk and unnecessary files safely.

Follow the steps to clean up disk on Windows Server 2008 (R2):

  1. Press Windows and R on your keyboard, type cleanmgr and then press Enter.
  2. Select C: drive and click OK.
  3. Click the check-boxes in front of the files that you want to delete and click OK.
  4. Confirm this operation by clicking Delete Files.

If you receive error that there's no cleanmgr, it means that Disk Cleanup is not installed in this server, follow the steps to enable Disk Cleanup on Server 2008.

Clean up disk

After these steps, you'll get some free disk space and Windows Server 2008 Low Disk Space warning will disappear. However, it doesn't mean you've solved this problem completely. As I explained above, you'd better add more free space to C drive.

Add more free space to system C drive

In most of servers, there's plenty of free space in other data volume such as D. Then you can shrink this volume with some tool, part of free space will be changed to Unallocated and all files keep intact. Finally, add this Unallocated space to system C drive. In this way, Operating System, programs and anything else keep the same with before except partition size.

Windows Server 2008 has native Disk Management and diskpart command tool to shrink partition without losing data (in most cases), but Unallocated space can't be added to C drive with these tools. You need server partition software to accomplish this task.

Better than other software, NIUBI Partition Editor is much safer and faster because of the advanced technologies:

Download NIUBI Partition Editor and follow the steps to fix low disk space on Windows Server 2008 (R2):

  1. Right click drive D and select "Resize/Move Volume", drag left border towards right in the pop-up window, or enter an amount in the box of Unallocated space before. Then part of unused space will be changed to Unallocated on the left of D.
  2. Right click drive C and select "Resize/Move Volume" again, drag right border towards right in the pop-up window, then Unallocated space will be combined to C drive.
  3. Click Apply on top left to execute, done.

If you want to add free space from a nonadjacent partition (such as E:), there's an additional step to move Unallocated space before adding into C drive.

Video guide

If you use any types of hardware raid arrays such as RAID 0/1/5/10 or running Server 2008 as virtual machine in VMware/Hyper-V, simply follow the steps in the video above. There's no difference if there's available free space on the same disk.

If there are no other volumes or no available free space on the same disk, no software can add space from another separated disk. In that case, follow the steps:

In Summary

When Low Disk Space alert pops up in Windows Server 2008 (R2), try to clean up disk to get some precious free space, to keep the server running in the right way. If you cannot reclaim plenty of free space, or C drive was created too small, add more free space from other volumes. Thanks to the advanced technologies, NIUBI Partition Editor helps accomplish this task fast and safely. It also helps you do many other disk partition operations.