Apparently windows 7 runs a boot defragmentation service automatically in the background while idle. In my case, it happened to run when my computer was anything but idle (but more on that later). This is separate from the scheduled task listed when you configure "Disk Defragmenter". I only discovered this after checking my system logs.
This isn't exactly new information and plenty of websites detail how to enable and disable it, see http://www.theeldergeek.com/automatic_boot_disk_optimization_[defrag].htm for details. It involves changing a registry key, and SSD users would want to disable it for obvious reasons.
However, HDD users still might want to disable it and change it to a scheduled event. Here's why: The windows idle-state doesn't seem to measure disk I/O when determining if the system was idle. For most scheduled tasks, who cares, but for defrag, that's kind of important. My reasoning for this, is that I had started downloading Portal 2 at about 20mb/s, came back a little bit later and heard the disk churning to hell. It was defragmenting while simultaneously writing data, and you can imagine what that sounds like. So either it ignored the I/O activity or deemed it insignificant. I've disabled this feature in the registry and moved it to a scheduled task.
Designed to run after 10 mins of idle.
This isn't exactly new information and plenty of websites detail how to enable and disable it, see http://www.theeldergeek.com/automatic_boot_disk_optimization_[defrag].htm for details. It involves changing a registry key, and SSD users would want to disable it for obvious reasons.
However, HDD users still might want to disable it and change it to a scheduled event. Here's why: The windows idle-state doesn't seem to measure disk I/O when determining if the system was idle. For most scheduled tasks, who cares, but for defrag, that's kind of important. My reasoning for this, is that I had started downloading Portal 2 at about 20mb/s, came back a little bit later and heard the disk churning to hell. It was defragmenting while simultaneously writing data, and you can imagine what that sounds like. So either it ignored the I/O activity or deemed it insignificant. I've disabled this feature in the registry and moved it to a scheduled task.