Comments on: File Systems – Which Need Defragmenting?

By: Larry Miller

Larry Miller — Wed, 24 Dec 2008 17:08:57 +0000

This article contains a number of errors.
The ext3 file system is not unique in being a journaled file system. NTFS has had this since it was introduced about 1993. In any event this feature has nothing to do with file fragmentation. The purpose of journaling is to help prevent the file system, but not necessarily individual files, from becomming corrupt. This was a common problem with FAT, FAT32, and other early file systems.

ALL modern file systems are subject to fragmentation to some degree. Some early systems avoided the issue by requiring that there be adequate contiguous space before a file could be saved but this caused other serious problems. Some systems incorporate features to minimize fragmentation but it cannot be entirely avoided. A fragmented file will take longer to read because of the nature of the storage medium, regardless of the file system in use. In some early systems fragmentation was not a serious problem because these effects were masked by more serious problems.

Larry Miller
Microsoft MCSA

By: Kelvin (Optimization) Nikkel

Kelvin (Optimization) Nikkel — Sun, 23 Mar 2008 00:10:00 +0000

Nice explanation of the differences in FAT, NTFS and HFS used by MAC. Personally, I have never used a MAC so have always had to manually defrag my system. That is until now.

As Jerico mentioned, there are some NICE behind the scene optimization tools for Windows. Also there are much better defrag tools than the default one that Windows gives you.

I have used JKDefrag (which is free) and I feel it does a much better job at defragmenting the hard drive than the default one.

By: Lew Miller

Lew Miller — Sun, 10 Feb 2008 19:29:52 +0000

The argument that the HFS+ system never needs to be de-fragmented is not quite right.

As this article, and others, explain, the jounalling and automatic file de-fragmentation features in OS X work to keep files in single pieces. To do so, the OS uses up segments of the “free” disk space. Eventually the “free” disk space becomes highly fragmented. Empirically, when that happens, the OS has little or no space in which to re-write the fragmented files.

Tech Tool Platinum illustrates this problem very graphically. When I run its optimization utility, there are usually relatively few fragmented files and file fragments. However, the number of “free-space” disk fragments are almost always enormous. Typical numbers might be:
98 fragmented files
124 file fragments
1,281 disk fragments

The graphical display will show many discontinuities in the blue blocks representing the data, which in extreme cases are distributed throughout the disk. It is not uncommon for half or more of the files to have been migrated to the “end” of the disk.

Consequently, Tech Tool’s optimizer disposes of the fragmented files very quickly, then spends considerable time clustering the files together at the “front” of the disk to create a single “free” fragment, which the OS then uses to de-fragment files again.

I have a 12″ PowerBook G4 and an iMac 20. Almost every time I run Disk Warrior and Tech Tool, the start-up and operating performance of the computers improves noticeably.

Therefore, I would argue that de-fragmentation is logical and justifiable, even in OS X.

By: anonymous

anonymous — Wed, 19 Dec 2007 18:28:11 +0000

Correction: Both NTFS and ext3 use metadata journaling. The actual data writes aren’t journaled, but any changes to the structure of the filesysem are. This means that you won’t get a corrupt filesystem if power fails, but you may get corrupt data.

By: tayeb

tayeb — Tue, 04 Dec 2007 22:17:59 +0000

it’s very good document

By: evermore

evermore — Tue, 04 Dec 2007 11:42:21 +0000

Whether files are fragmented or not is not the only reason to use a defragmenter. By default most defrag programs also arrange files in order to speed up access. (The built-in Windows defrag only arranges executables based on prefetch data.) Different programs do it differently. Some will move recently modified files to the faster part of the disk/partition on the assumption that you want faster access to those. Others move the recently modified files to reside after all other files, so that when they’re modified again and may become larger, the drive heads don’t have to travel from a location at the beginning of the disk to farther inward in order to write the extra data. Some let you specify where certain types of files get placed. Most will also move and defrag system files which the Windows defrag will not, resulting in better performance when loading those files, since installing updates will result in some files changing a lot.

By: Bob

Bob — Mon, 03 Dec 2007 15:00:20 +0000

Vista and Server 2008 use Transactional NTFS this is what makes both more secure than Windows 2000/XP. Vista is designed to defragment the hard drive on a shedule. Most probably Server 2008 will also perform the task automatically. Unlike Windows 2000/XP there is hardly any speed boost from running defrag with Windows Vista, at least I haven’t gained anything from doing so as of yet.

By: jericho

jericho — Mon, 03 Dec 2007 09:21:42 +0000

With very good automatic background defragmenters available for NTFS currently, XP and Vista don’t need to manually defragged or scheduled periodically to keep them running smoothly. These auto defraggers run in the background, taking up barely any memory and monitor fragmentation. If necessary, defragmentation occurs quietly in the background when there are free system resources, so other, primary computing activities are not affected. It’s an elegant and easy solution to the fragmentation problem.

I think Macs do something roughly similar, but i could be wrong, since I haven’t used OSX for a while now.

By: Bob Plumer

Bob Plumer — Mon, 03 Dec 2007 03:10:11 +0000

Thanks for the article. Very well done.

By: Malcolm

Malcolm — Sun, 02 Dec 2007 16:19:04 +0000

NTFS is a journaled file system, and journaling isn’t the reason that EXT3 doesn’t require defrag