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Backup slows/stalls at 8% (various clients) RRS feed

  • Question

  • Hi,

    My WHS has been running successfully for several years -- backs up half a dozen computers each day. Backups usually take 15 to 20 minutes per computer depending on network speed (some via wireless), disc size, etc.

    Two days ago, ALL the clients started to experience slow backups. Backup time is suddenly over three hours per client. The backups seem to run alomg fie until they reach 8%, and then stall there for a long time. They do progress to 9% and 10% and so on, and then towards the end (not exactly sure when), they speed up again and finish.

    Clearly something has changed or gone wrong. The WHS machine has not changed during in the last few days, although I did add a new 1.5TB drive a week ago. However four or five sets of backups ran fine at usual speed after I added the new drive, and now I have this slowing down issue.

    Task Manager on the WHS box shows CPU usage at 10% - 15% during the first 8% of the backup, then jumping to 55% (or so) when the backup stalls (reading at the bottom of the Task Manager window). However the 'processes' tab in task manager doesn't show what is using the CPU. Mostly it shows System Idle Process at 95% to 98%, and when whsbackup.exe floats to the top of the list it's never more than about 2%.

    Clients are a mix of Win 7 and Vista. No new clients recently added. WHS storage is less than 50% full. Two of the not-new drives are over 90% filled. All drives report 'healthy'. Srever has been restarted but no change.

    Any ideas? Has an 'update' been released recetly that may be causing this behaviour?

    Thoughts and ideas appreciated.

    R.

    Friday, May 20, 2011 2:08 PM

Answers

  • Solved. I went down a blind alley with DEMIGRATOR. Turns out that one of my drives had been somehow marked for PIO communications, and the hardware interrupts were driving the machine crazy. I deleted the controller in device manager, and it was redetected (after restart) at the correct speed, and now all is well.
    • Marked as answer by richardnau Saturday, May 28, 2011 7:43 AM
    Saturday, May 28, 2011 7:43 AM

All replies

  • Update: backup last night on one machine took 8 hrs and 42 minutes...
    Saturday, May 21, 2011 1:05 AM
  • Further info:

    It's now more than a week and the system is slower than ever. Backups now take 8 hours.

    Problem SEEMS to be related to disk rebalancing and DEMIGRATOR.EXE. A little bit of sleuthing shows that:

    • hard disk access speed is fine (around 20,000 kB/s) for the first few per cent of the backup after a system restart
    • then at around 8%, DEMIGRATOR.EXE starts up, hard disk speed slows to around 1,600 kB/s and the backup effectively slows to a creep (first 7% of a backup takes less than a minute, then it slows)
    • the 'system' drive (1TB) is nearly empty
    • second drive (1TB) is about 82%
    • third drive (1TB) is about 40%
    • fourth drive (new, 1.5TB) is about 25%.

    Before I installed the new (1.5TB) drive, the second and third drives were both abt 95% full.

    Do I just need to wait another week for DEMIGRATOR to finish rebalancing? Will it ever finish? Is there anything I can do to hasten its work?

     

    Thanks.

    • Marked as answer by richardnau Saturday, May 28, 2011 7:43 AM
    • Unmarked as answer by richardnau Saturday, May 28, 2011 7:43 AM
    Friday, May 27, 2011 10:59 PM
  • Solved. I went down a blind alley with DEMIGRATOR. Turns out that one of my drives had been somehow marked for PIO communications, and the hardware interrupts were driving the machine crazy. I deleted the controller in device manager, and it was redetected (after restart) at the correct speed, and now all is well.
    • Marked as answer by richardnau Saturday, May 28, 2011 7:43 AM
    Saturday, May 28, 2011 7:43 AM