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Server not rebalancing RRS feed

  • Question

  • I have an HP Mediasmart server.  Came with a 750 GB drive and I added three more.  The OS drive usually showed 0% used while the other drives were nearly 80% full.  So I replaced the three 750 GB drives with 1 TB drives, leaving the OS drive alone.  For some reason, the files that were moved to the OS drive are still there.  It's showing 45% of the space is used, and the last storage drive I added is only using 5%.  The other two storage drives are showing 70 and 68% respectively.

    It's been like this for about four days now.  When will the files move off the OS drive??  I understand the OS sits on a 40GB partition, but I'm not used to seeing any file usage on that drive.

    Thanks for your help!

     

    -Matt

    Wednesday, September 14, 2011 5:13 AM

Answers

  • Windows Home Server won't move files around unless a drive is almost completely full, so what you're seeing is normal behavior.
    I'm not on the WHS team, I just post a lot. :)
    Wednesday, September 14, 2011 11:20 AM
    Moderator

All replies

  • Windows Home Server won't move files around unless a drive is almost completely full, so what you're seeing is normal behavior.
    I'm not on the WHS team, I just post a lot. :)
    Wednesday, September 14, 2011 11:20 AM
    Moderator
  • I'll have to take your word for it; but it's a good word.  ;)

    I installed those extra three drives before I used the server for anything, and after loading the server up with backups and files and such it never put files on the OS drive; it always stayed at 0%.  It's just curious that it is using the OS drive.  I thought that drive was just for tombstones and a landing zone for transferred data/files before they were moved to the storage drives?

    Thursday, September 15, 2011 12:47 AM
  • The algorithm used to determine where to put a file is proprietary, of course, but quite some time ago Microsoft gave some general rules:

    1. It tries to keep a small (20 GB, IIRC) amount of space free on all drives, as a buffer.
    2. It tries not to use the system drive if it can avoid doing so.
    3. It tries to put files on the drive(s) that has the least free space, as long as it doesn't violate the buffer. The logic here is that this tends to keep files in the same share together, since you tend to move files to your server and leave them, rather than move them around on your server.
    4. It doesn't shuffle files around unless a drive is over-full.

    The result is that, when you start adding and removing drives, you usually wind up forcing files onto your system drive at some point, and they don't move back off. It doesn't really matter; there's no measurable performance impact, and it won't reduce the life of the system drive.

    In your case, you started with 4 drives, so the server managed to keep your system drive empty until you started shuffling drives. Then it had to move stuff to the system drive, and it left the files there when you added more space.

     


    I'm not on the WHS team, I just post a lot. :)
    Thursday, September 15, 2011 3:07 AM
    Moderator