# Defragmenting: why so long? **URL:** \ **Category:** Factual Questions\ **Created:** [March 14, 2009, 5:07am UTC](https://boards.straightdope.com/t/defragmenting-why-so-long/489402 "2009-03-14T05:07:48Z")\ **Posts on this page:** 7\ **Page:** 2
**Author:** ![Markxxx](https://avatars.discourse-cdn.com/v4/letter/m/5daacb/32.png) [@Markxxx](https://boards.straightdope.com/u/Markxxx)\ **Post date:** [March 15, 2009, 9:44pm UTC](https://boards.straightdope.com/t/defragmenting-why-so-long/489402/21 "2009-03-15T21:44:02Z")
How would a defragger effect a torrent file. Since those are already in pieces seems like the potential to mess them up is a lot ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [March 15, 2009, 10:03pm UTC](https://boards.straightdope.com/t/defragmenting-why-so-long/489402/22 "2009-03-15T22:03:11Z")
> [@Markxxx](#): > > How would a defragger effect a torrent file. Since those are already in pieces seems like the potential to mess them up is a lot The potential to “mess up” a file is no greater for one file than another, if you mean an error that distorts or modifies the file. And almost ALL files, unless just after a defrag, are in pieces anyway, i.e., scattered in non-contiguous areas. Certainly the fact that you are changing directory entries and moving almost all the data on a hard drive around means that the potential for mistakes is high. Turning off the computer (or a power outage) in the middle of such sensitive operations is discouraged, although defraggers nowadays are safer to use than long ago. Basically, if the file data, or part of it, is physically moved to another cluster/sector/track or cylinder, the directory entry must be changed to reflect that “simultaneously.” Problems arise when data is moved but the directory entry isn’t updated, or vice-versa. So I tend to use them sparingly. Your data can’t be messed up if you don’t read and write it, and it can if you do. ---
**Author:** ![Rysto](https://avatars.discourse-cdn.com/v4/letter/r/ecccb3/32.png) [@Rysto](https://boards.straightdope.com/u/Rysto)\ **Post date:** [March 15, 2009, 10:08pm UTC](https://boards.straightdope.com/t/defragmenting-why-so-long/489402/23 "2009-03-15T22:08:56Z")
> [@Markxxx](#): > > How would a defragger effect a torrent file. Since those are already in pieces seems like the potential to mess them up is a lot torrents, to my knowledge, are only _downloaded_ in pieces. The torrent client puts the pieces back together in the right order to form the full file. ---
**Author:** ![dougie\_monty](https://avatars.discourse-cdn.com/v4/letter/d/439d5e/32.png) [@dougie\_monty](https://boards.straightdope.com/u/dougie_monty)\ **Post date:** [March 16, 2009, 3:53am UTC](https://boards.straightdope.com/t/defragmenting-why-so-long/489402/24 "2009-03-16T03:53:49Z")
> [@Rigamarole](#): > > I don’t understand why you needed to have “time on your hands” to defrag a drive. Can’t you just run it while you go eat/sleep/watch a movie/read a book/plot to take over the world? That’s what I usually do. It’s not that simple. Sometimes a large project will hit a snag and a dialog box pops up. "Shall this defragmentation/dishcheck/installation/whatever continue?’ I don’t want to let the computer sit like that for four hours only to find out it’s sat there for 3 1/2 hours waiting for me to click a Yes or No button! ---
**Author:** ![GusNSpot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gusnspot/32/436_2.png) [@GusNSpot](https://boards.straightdope.com/u/GusNSpot)\ **Post date:** [March 16, 2009, 5:11am UTC](https://boards.straightdope.com/t/defragmenting-why-so-long/489402/25 "2009-03-16T05:11:35Z")
The joys of smaller multiple drives. Fast, fast, fast. Easy cloning and fast. De frag is faster not often needing defragging because it only has a few big things on it and I don’t get those pesky dialog boxes. YMMV ---
**Author:** ![Rigamarole](https://avatars.discourse-cdn.com/v4/letter/r/77aa72/32.png) [@Rigamarole](https://boards.straightdope.com/u/Rigamarole)\ **Post date:** [March 16, 2009, 10:04am UTC](https://boards.straightdope.com/t/defragmenting-why-so-long/489402/26 "2009-03-16T10:04:10Z")
> [@dougie\_monty](#): > > It’s not that simple. Sometimes a large project will hit a snag and a dialog box pops up. "Shall this defragmentation/dishcheck/installation/whatever continue?’ I don’t want to let the computer sit like that for four hours only to find out it’s sat there for 3 1/2 hours waiting for me to click a Yes or No button! I guess you have a crappy defrag program, because mine has never done that on Windows XP. ---
**Author:** ![dougie\_monty](https://avatars.discourse-cdn.com/v4/letter/d/439d5e/32.png) [@dougie\_monty](https://boards.straightdope.com/u/dougie_monty)\ **Post date:** [March 17, 2009, 6:00am UTC](https://boards.straightdope.com/t/defragmenting-why-so-long/489402/27 "2009-03-17T06:00:44Z")
> [@Rigamarole](#): > > I guess you have a crappy defrag program, because mine has never done that on Windows XP. W-ell, mine hasn’t either, but of late I’ve been running some other programs (including one involving copying nearly 4000 photos off a CD!) and I’ve been playing it safe. My defragmentation program never did in fact bring up a dialog box. [Previous page](https://boards.straightdope.com/t/defragmenting-why-so-long/489402.md?page=1)