Adding a Disk Drive to an already full Windows Home Server

It’s time to upgrade my storage in my HP MediaSmart Server.  My goal is to remove one of the 500 Gb drives in my server and replace it with a 1Tb drive.


It’s evident by this screen capture that my drives are at capacity.  The system drive has 348 Gb free but the other three drives have anywhere between 448Gb to 450Gb used.  It’s not shown very well by my screen shots but the sum of free disk space is less than what would be required to move the data from one of my data drives if I were to run the drive removal wizard at this point.  If I were to attempt to remove a drive via the Server Storage tab there I would be informed by the wizard that there is not enough disk capacity to do so.  The remove disk wizard attempts to transfer data on the drive you want to remove to free space elsewhere on the server.

Looks like I need to clean house a little bit or add some external storage temporarily.


I removed a computer/backup that was old and that freed up space on the third drive (Disk 2) in my system as shown by this screen capture.(the one highlighted is the fourth drive)

Since all four of the drives are 500Gb drives I really don’t care which one I remove so Disk 2 will be coming out.  With 348 Gb free on the System drive it should easily take the data from Disk 2.

I initiated the disk removal wizard on disk 2 and in fact WHS moved it’s data to Disk 0.


You can see by this shot that WHS was successful in transferring the data so I can remove the drive.


Here is what it looks like after the wizard has readied the drive for removal.  The HP MediaSmart Server is a Hot Swappable server so you can remove and add hard drives with the server powered up.  I removed the old drive while watching the Server Storage tab and within seconds the drive disappeared.  I gently slid in the new drive and again, in seconds, it appears as new storage but with attention required in order to use it.


There are no wizards that pop up and ask you what you would like to do with your new drive so you will have to click the drive and then choose Add.

The following screen shots take you through the Add a Hard Drive Wizard.






It’s done quickly so don’t blink!


A quick look at Server Storage shows plenty of drives space now!


You might think by looking at this last screen shot that WHS is not balancing the drives correctly.  It is though.  WHS will not start transferring data to my new drive until the others have only 10Gb or less of data on them.  It might not look pretty but this is how it was designed.  The best explanation I could find on balancing was on Chris Gray’s MSDN Blog.

“Balancing solve(s) the problem of how to handle disk space imbalances. Just like duplication, balancing occurs every hour in PP1. The need to balance occurs typically with addition of a new volume or when the user deletes a bunch of files. The goal of balancing is to move files off any volume that contains less than 10GB of free space. If this condition happens we say the volume has reached a “danger” level because it’s possible to have a situation where files cannot be extended.”  “The PP1 balancing algorithm starts only when a volume contains less than 10GB of free space. When this occurs the goal is to start moving files to volumes with more space until 20GB is reached.”


I have let a week go by and my new drive is starting to fill up.  You will see in the last screen shot that it’s currently at 2% and my new files are being transferred to it when I save to my shares.


My parting thought is that you should think about swapping in larger drives before your other drives get full in order to make the swap as easy as possible.  If you don’t, you might be looking at some cleanup or possibly adding some temporary USB drives to help facilitate the swap.  I know what you’re thinking.  Use the Disk Balancer utility to balance up those drives.  Don’t think I haven’t thought about it but I’m willing to let Windows Home Server perform as designed for the time being.

If you have encountered such a situation I am interested to hear what your methods were.

Lastly, this article was partly made possible by the fantastic Add-In, Windows Home Server Disk Management, by Sam Wood.  Thanks for a great Add-In Sam.

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3 Responses

  1. pwestbro says:

    There are several other options, that I have used, when I upgraded my server.

    1) Turn off duplication on a share, where you have the data backed up somewhere else, just in case.

    2) Temporarily attach an external USB drive that has as much space as the drive that you are replacing. Then when you are done adding the new drive, you can remove the external drive

  2. AwesomeSpaceMonkey says:

    I'm just starting to research WHS to build my own server. This post states that you had to copy the data off the drive before you upgraded it. So the data was not duplicated on another drive in the server? What if your Disk 2 had failed before your upgrade? Would the data have been lost?

  3. Homeserver says:

    @pwestbro – Yes, good option. If you use an external drive somewhere on your network, copy some big files over to free up some space.

    @SpaceMonkey – In my article I didn't need to move files off to free up space. I deleted an old computer that was on my WHS at one time. When I deleted it WHS also deleted the backups and then I had enough space to remove a drive. If that drive had failed it would be business as usual for WHS. Anything that was on the drive that was duplicated would be safe.

    I suppose it can be confusing when dealing with removing drives. That's why the wizard is there to keep you safe and let you know when it's safe to remove the drive and put in a larger one.

    I could have copied files from the WHS to an external drive to free up space but in my case that was not necessary.

    If this doesn't make sense send me a message and I'll try to break it down further.

    Thanks for your comments!