# De Frag **URL:** \ **Category:** Factual Questions\ **Created:** [January 6, 2001, 1:18am UTC](https://boards.straightdope.com/t/de-frag/48664 "2001-01-06T01:18:30Z")\ **Posts on this page:** 10\ **Page:** 3
**Author:** ![Irishman](https://avatars.discourse-cdn.com/v4/letter/i/b487fb/32.png) [@Irishman](https://boards.straightdope.com/u/Irishman)\ **Post date:** [July 31, 2001, 9:46pm UTC](https://boards.straightdope.com/t/de-frag/48664/41 "2001-07-31T21:46:24Z")
I wish I understood what everyone is saying. Half this stuff is whizzing over my head. But I think I’ve been having this problem - defrag not running fully but restarting, or locking up. Especially with Maintenance Wizard. I will try the safe mode Scandisk, then defrag. ---
**Author:** ![barbitu8](https://avatars.discourse-cdn.com/v4/letter/b/839c29/32.png) [@barbitu8](https://boards.straightdope.com/u/barbitu8)\ **Post date:** [July 31, 2001, 10:01pm UTC](https://boards.straightdope.com/t/de-frag/48664/42 "2001-07-31T22:01:59Z")
> [@](#): > > \*Originally posted by bdgr \* > \*\*REboot in safe mode, run defrag from there. to get to safe mode, hit F8 at bootup when you get the msg starting windows 9x. you will get a menu, with the option for safe mode. \*\* Microsoft Help says hit CTRL at bootup to get to safemode. I read somewhere to hit both CTRL + F8. Not having tried this yet, I don’t know which if any, or all, will work. MannyL said on 1/5/01 that he was never able to fully defrag in safemode. Is this true? Has anyone else had that problem, before I try that? ---
**Author:** ![Johanna](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johanna/32/8318_2.png) [@Johanna](https://boards.straightdope.com/u/Johanna)\ **Post date:** [August 1, 2001, 3:56am UTC](https://boards.straightdope.com/t/de-frag/48664/43 "2001-08-01T03:56:54Z")
A tech guy told me once it isn’t a good idea to defrag too often. ScanDisk is safe to run as much as you like, but you should wait until the disk is a certain amount fragmented before running defrag. Anything to this? ---
**Author:** ![handy](https://avatars.discourse-cdn.com/v4/letter/h/b5a626/32.png) [@handy](https://boards.straightdope.com/u/handy)\ **Post date:** [August 1, 2001, 2:58pm UTC](https://boards.straightdope.com/t/de-frag/48664/44 "2001-08-01T14:58:55Z")
Hold CTRL to get the MENU. From the MENU you can select DOS or Safe mode etc. Defrag all you want Jomo. It might be unnessary sometimes but its safe. Also defrag the registry. ---
**Author:** ![bdgr](https://avatars.discourse-cdn.com/v4/letter/b/a87d85/32.png) [@bdgr](https://boards.straightdope.com/u/bdgr)\ **Post date:** [August 2, 2001, 2:33pm UTC](https://boards.straightdope.com/t/de-frag/48664/45 "2001-08-02T14:33:18Z")
> [@](#): > > \*Originally posted by Jomo Mojo \* > \*\*A tech guy told me once it isn’t a good idea to defrag too often. ScanDisk is safe to run as much as you like, but you should wait until the disk is a certain amount fragmented before running defrag. Anything to this? \*\* No. I suppose it does put a little extra wear on the hard drive, but considering that hard drive will be completely obsolete in just a few years, it should outlast its usability anyway. ---
**Author:** ![barbitu8](https://avatars.discourse-cdn.com/v4/letter/b/839c29/32.png) [@barbitu8](https://boards.straightdope.com/u/barbitu8)\ **Post date:** [August 2, 2001, 4:42pm UTC](https://boards.straightdope.com/t/de-frag/48664/46 "2001-08-02T16:42:21Z")
I went to Safe Mode last night and first used Scan Disk. That took almost six hours. During the first hour, it kept going back to start and then gave me the note that it has done that 10 times already. So I clicked don’t tell me again and went away from the computer, to return a few hours later, and it apparently did not do it after the first hour. I timed the rate and it was about 5,000 clusters a minute and I had a total of 1,217,000 clusters. What the heck is a cluster? On the details, they are laid out in tiles. Then I started the defrag and I knew I wouldn’t complete it before bedtime, but wanted to see how it progressed. In just a few minutes, it was 30% finished, with no returns to start, but then it bogged down. I toggled down (not the right term, but I can’t think of the right one now) to see how the rest looked, and there were just a few empty tiles before the clusters ended and I had all white. So with not much fragmentation, I canceled and went to bed. Thanks to all who have tried to help. Three more questions. What’s a cluster? Why did it take 6 hours to Scan Disk in Safe Mode, and is that usual? Incidentally, no errors were found. ---
**Author:** ![yabob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yabob/32/2821_2.png) [@yabob](https://boards.straightdope.com/u/yabob)\ **Post date:** [August 2, 2001, 5:32pm UTC](https://boards.straightdope.com/t/de-frag/48664/47 "2001-08-02T17:32:24Z")
> [@](#): > > \*Originally posted by bdgr \* > \*\* > > > [@](#): > > > > \*Originally posted by Jomo Mojo \* > > \*\*A tech guy told me once it isn’t a good idea to defrag too often. ScanDisk is safe to run as much as you like, but you should wait until the disk is a certain amount fragmented before running defrag. Anything to this? \*\* > > No. I suppose it does put a little extra wear on the hard drive, but considering that hard drive will be completely obsolete in just a few years, it should outlast its usability anyway. \*\* Actually, it probably isn’t bad advice just on the grounds that a defragmentation program is something that has potential to really screw up your filesystem if it had a bug. The windows defragger is pretty solid and it’s not likely, but why run the risk when it doesn’t need to be done? BTW, a cluster is a grouping of disk sectors. Disks are divided into physical sectors, usually 512 bytes. It is sometimes conveniant for the minimum block size the filesystem works in to be bigger than this, so the sectors are lumped into “clusters” (Windows calls them “allocation units”). For Windows FAT filesystems, you are only allowed 65536 clusters per partition, so in order to make use of larger disk space within a partition, you have to increase the cluster size. The down side to having a large cluster size is that small files then waste a lot of space. Some of these disk analysis programs will report “cluster overhang”, which is a term for waste space because of leftover bytes in the clusters. ---
**Author:** ![barbitu8](https://avatars.discourse-cdn.com/v4/letter/b/839c29/32.png) [@barbitu8](https://boards.straightdope.com/u/barbitu8)\ **Post date:** [August 2, 2001, 6:05pm UTC](https://boards.straightdope.com/t/de-frag/48664/48 "2001-08-02T18:05:23Z")
> [@](#): > > \*Originally posted by yabob \* > \*\* For Windows FAT filesystems, you are only allowed 65536 clusters per partition, so in order to make use of larger disk space within a partition, you have to increase the cluster size. The down side to having a large cluster size is that small files then waste a lot of space. Some of these disk analysis programs will report “cluster overhang”, which is a term for waste space because of leftover bytes in the clusters. \*\* Isn’t there a program, similar to defragging, which can eliminate the cluster overhang? If it’s possible to eliminate spaces between clusters, why isn’t it possible to eliminate space in a cluster? ---
**Author:** ![Joe\_Cool](https://avatars.discourse-cdn.com/v4/letter/j/ecb155/32.png) [@Joe\_Cool](https://boards.straightdope.com/u/Joe_Cool)\ **Post date:** [August 2, 2001, 6:10pm UTC](https://boards.straightdope.com/t/de-frag/48664/49 "2001-08-02T18:10:06Z")
> [@](#): > > \*Originally posted by Sue Duhnym \* > \*\*I ran my defrag overnight (about 10 hours) about two weeks ago. > > I went to bed when it was about 20% “complete” and I woke up to 12%. > > I finally cancelled it, thinking it was hopeless as it kept saying that “disk contents changing” (paraphrasing) and would start all over. > > WTF? \*\* Sue, I really doubt your problem is related to the swap file. It’s possible, but not likely. You might want to try MannyL’s suggestion, otherwise try this: First, get into safe mode. The easiest way is to boot while holding down the Shift key. Once the windows splash screen comes up, you can let go. When safe mode boots fully, press Ctrl + Alt + Delete and make sure nothing is running in the task list except explorer. When that’s done, first run Scandisk with “Automatically fix errors” checked. Standard scan is fine, no need to run thorough unless you want to burn an extra hour, or unless you suspect problems with the hard drive or file system. After scandisk is done, close it and run defrag again. You shouldn’t have any further problems. If it’s still telling you that something is writing to the hard drive, then it’s conceivable you may have a virus. If you have more problems, my e-mail is in my profile. ---
**Author:** ![barbitu8](https://avatars.discourse-cdn.com/v4/letter/b/839c29/32.png) [@barbitu8](https://boards.straightdope.com/u/barbitu8)\ **Post date:** [August 2, 2001, 6:25pm UTC](https://boards.straightdope.com/t/de-frag/48664/50 "2001-08-02T18:25:46Z")
> [@](#): > > \*Originally posted by Joe\_Cool \* > \*\* First, get into safe mode. The easiest way is to boot while holding down the Shift key. Once the windows splash screen comes up, you can let go. When safe mode boots fully, press Ctrl + Alt + Delete and make sure nothing is running in the task list except explorer. > > When that’s done, first run Scandisk with “Automatically fix errors” checked. Standard scan is fine, no need to run thorough unless you want to burn an extra hour, or unless you suspect problems with the hard drive or file system. That’s why it took me so long. I did the thorough Scandisk. Also after getting into Safe Mode, I did not delete anything. I thought SafeMode is a mode wherein nothing runs except the essentials. But I got into SafeMode by holding down the Control key, not the Shift key. [Previous page](https://boards.straightdope.com/t/de-frag/48664.md?page=2)