Expand Windows Server 2008 RAID 5 array

Solution 1:

It would appear that the short answer is "No" - a Windows RAID-5 array cannot be expanded (safely) once it has been made. So make sure you get enough headroom in it in the first place, or buy a proper RAID controller that supports online expansion!

Solution 2:

I think you could add the disks to the array and then use something like Partition Magic (or Partimage) to increase the size of the partition on the array of disks.

Regardless, you need a backup. RAID is not a backup strategy (as has been written many times in this site). Schedule the system downtime for immediately after the backup has completed, and be ready to restore.

Solution 3:

I had the same problem with Windows Server 2003 (not able to expand a Windows RAID-5 array),

I ended up writing a program that does the trick (expand an NTFS partition on a dynamic RAID-5 volume, it also has the ability to recover from a drive failure during the expansion process)

The on-disk structure for Server 2003 and 2008 is the same, however my program operates differently under Windows Server 2008 and takes all the dynamic disks offline (necessary for direct disk access) instead of locking the disks and volumes.

You should test it on a smaller scale before using it. Be sure to back up all of your important data.

Both my program (Dynamic Disk Partitioner) and its source code are available here