I have a fileserver that is starting a defrag around 2:00 PM everyday. This is killing performance as it runs for ours becuase this is a file server and has multiple drives. All scheduled tasks regarding defrag have been disabled.
I have verified that it is accessing the data drives(using SysInternals tools). The reason I might have though otherwise was the event log has multiple entries regarding defragging a db file related to shadow copies. Oh yes these drives take shadow copy snapshots multiple times per day but the times of them don't coincide with the defrag task.
There is nothing in the event logs regarding defrag except those noted above in relation to shadow copies.
I'm out of ideas looking for what is starting these jobs. One possiblility is that the drives are not being defgramented, but being analyized to determine if they need to be defragmented. I manually ran an analysis and the cpu usage(by dfrgntfs.exe) seems to be similar to what I'm seeing everday while the defrag process is running. However I've found no setting that schedules this analysis.