Back in June 2009 I picked up a copy of PerfectDisk for Windows Home Server as a solution for defragmenting the system. At the time I hadn't expanded things too far storage-wise, but since then I've increased my storage capacity to nearly 8TB.

Between June and December 2009, I noticed I would get reasonably frequent (roughly weekly) health warnings on my system drive. Running a "repair" on the drive would return things to normal. I prepared myself for it to fail, researching how to recover, replace the system disk, etc. In the meantime, I decided to stop running PerfectDisk on it since the system drive never really got any more fragmented than it already was. Why strain a failing drive, right?

Stopping PerfectDisk on my system drive stopped the health warnings from showing up. It's been several months (maybe four) since I stopped running PD on that drive and I've not seen a single health warning. Failing drive... or PerfectDisk? Before you answer, let me finish the story.

Toward the latter half of the year, a couple of months into my PerfectDisk usage, I noticed that things would lock up on the system occasionally such that you couldn't access the Windows Home Server console, you couldn't connect to the Remote Desktop, and you couldn't access any file shares. You had to power down hard and reboot to get things responding again. Looking in the event logs, I saw what looked like hardware issues:

Source: disk
Error: The device, \Device\Harddisk5, is not ready for access yet.

Source: mv61xx
Error: The device, \Device\Scsi\mv61xx1, did not respond within the timeout period.

Sounds hardware-ish to me, and that worries me. It always seemed to happen when I was running a scheduled task that backed up some data to another computer on my network (so there was a lot of disk I/O) and the PerfectDisk full defrag was running at the same time. On a hunch, on December 27, 2009, I stopped PerfectDisk from running on my system by disabling all of the jobs.

Windows Home Server started running without a single disk or mv61xx error. As part of my recent storage upgrade issue (where I got an incompatible drive) I ended up running extended diagnostics (both "chkdsk /x /r" and Western Digital disk diagnostics) on all of the drives in the system with no errors detected. Again, no errors - all the way through to yesterday, over a month later.

Yesterday I re-enabled PerfectDisk and set it to run a full defrag. Around 30 minutes into the full defrag, I decided to sync my iPod and all of my music is on the Windows Home Server.

Lockup.

Looking in the error log - same errors as before from "disk" and "mv61xx."

Since I was able to run a bunch of diagnostics on the disks with no issues, I have a rough time thinking it's a hardware problem. I might buy that there's a driver issue and PerfectDisk brings it out by doing so much disk I/O so fast or something, but I don't have any evidence to back it up. I did notice that when I see these errors, they seem to be related to the disks in my eSATA port multiplier, so maybe something is going on there. Again, I can cruise along for months with no issues, streaming videos, streaming music, sharing files, etc., until I run PerfectDisk, so I have a rough time thinking there's no connection at all.

I'm currently working through this with PerfectDisk support, but so far they are calling "hardware issue" claiming they "use the Microsoft-provided defrag APIs." I'm curious if the defrag APIs don't quite work the same for Windows Home Server and/or if they don't work nicely with my eSATA setup.

I'll update this post if I find out anything new. Until then, I've got PerfectDisk disabled and I'm thinking, worst-case-scenario, I'm out the $40 I paid for the license.

UPDATE 6/16/2010: It appears that the WD Green drives I was using were not performing well. Removing them from the system allowed PerfectDisk to function properly.