Disk Defragmenter


chmorley

macrumors 6502a
Jan 2, 2002
602
2
Denver, CO
Re: Disk Defragmenter

Originally posted by jrbohorquezg
Does anyone know of a good disk defragmenter that runs natively on OSX? (besides norton utilities).
The only one that runs natively in OS X is Drive 10.

Chris
 

MacBandit

macrumors 604
Originally posted by mmmdreg
does defragging make a considerable difference in performance?

It can make a noticeable difference in performance when it hasn't been done in a while. It can also as I found in OS 9 help prevent disc related errors.

CAUTION!!

Always back-up your entire disc or important files before defragmenting. This action can lead to a total loss of the disc. It is rare but it can happen.
 

bousozoku

Moderator emeritus
Jun 25, 2002
13,951
3
Gone but not forgotten.
Originally posted by mmmdreg
does defragging make a considerable difference in performance?
It doesn't make so much of a difference as with Windows machines. The HFS and HFS+ file systems are based on a more advanced way of tracking the information so it degrades more slowly as things move around the disk.

The interesting thing is that goes way back to when the Macintosh first supported a hard drive. It was unthinkable for a small machine to use a B(inary)-Tree structure. :)
 

awrc

macrumors regular
Apr 20, 2002
215
1
Milwaukee, WI
Originally posted by bousozoku


It doesn't make so much of a difference as with Windows machines. The HFS and HFS+ file systems are based on a more advanced way of tracking the information so it degrades more slowly as things move around the disk.
More advanced than FAT/FAT32 perhaps, but NTFS is similarly "fragmentation resistant" (i.e. both NTFS and HFS+ need a good hard defrag every now and again).

Actually, on XP the layout.ini files have the potential to make defragmentation very effective in improving disk performance. They basically record the order in which files are accessed during system boot, so the OS can do neat preloading and cacheing tricks. It can also ensure that during defragmentation the files are placed near-optimally to minimize head travel, since it knows the order in which they'll be accessed (I say "near" because as far as I know none of the available defraggers try to take into account rotational latency, and so forth).

I wouldn't mind seeing something similar (but less kludgey) on a future Mac file system. Maybe something that extended it beyond just the system boot to individual applications.

I just defragged my new 10.2 install using Speed Disk under OS 9 (since Speed Disk 7.0.1 has Jaguar difficulties and Norton's lack of a custom install (I don't want your File Saver installed) means that it's persona non grata on my boot disk). While the layout is probably far from optimal, I was struck by the number of files it had to move around - 180,000+. That's the OS, my Adobe tools, my Macromedia tools, Painter 7, two or three games, and not a lot more. I've defragged similarly "loaded" PC drives where the file total has been around 40,000 - I guess Mac apps like lots of little files.
 

bousozoku

Moderator emeritus
Jun 25, 2002
13,951
3
Gone but not forgotten.
Yes, IBM's design for HPFS, oops NTFS, was very good and is still quite consistent with today's drives. I'm surprised that it's as slow as it is though. I expected much more speed considering what IBM did with HPFS when OS/2 jumped to 32-bit.

I'd like to see a Macintosh with enough hard drives to make fragmentation useful.

IBM's OS/400 spreads files across all the drive mechanisms so that any part of the file is equally close and can be quickly accessed. This is particularly useful for server systems such as IBM's iSeries (AS/400) where database access is 90 percent of what it does.

Apple would be wise to make use of such a scheme for their servers.
 

firewire2001

macrumors 6502a
Apr 2, 2002
718
0
Hong Kong
Originally posted by Future Man
You Could do it from 9 with Tech Tool Pro.
its not recommended to run a defragger built for os 9 to defrag an x drive - in fact it can corrupt it..

use with caution, or not at all...

-f
 

MacBandit

macrumors 604
Originally posted by firewire2001


its not recommended to run a defragger built for os 9 to defrag an x drive - in fact it can corrupt it..

use with caution, or not at all...

-f
This is true but Norton and Techtool both have defraggers that will defrag an X drive but will not run natively in X therefore you need to run it in 9 to defrag X. I believe that's what Future Man was referring to.
 

zarathustra

macrumors 6502a
Jul 16, 2002
770
0
Philadelphia, PA
Originally posted by bousozoku
YIBM's OS/400 spreads files across all the drive mechanisms so that any part of the file is equally close and can be quickly accessed. This is particularly useful for server systems such as IBM's iSeries (AS/400) where database access is 90 percent of what it does.

Apple would be wise to make use of such a scheme for their servers.
Are you talking about a RAID array?
 

chmorley

macrumors 6502a
Jan 2, 2002
602
2
Denver, CO
Originally posted by mmmdreg
does defragging make a considerable difference in performance?
Yes.

Anything that can help your processor work more easily makes a difference. Making files contiguous makes a difference in any OS. Imagine being able to read an article from one magazine versus having to read it from 10 different ones. The extra work of switching magazines is wasted energy, regardless of your brain power.

And Drive 10 is the only OS X native defragger.

Chris
 

bousozoku

Moderator emeritus
Jun 25, 2002
13,951
3
Gone but not forgotten.
Originally posted by zarathustra


Are you talking about a RAID array?
Not at all. This method of spreading things came around in the IBM labs in the mid-1980s but in the past 7 years has been able to run with various levels of RAID.

RAID keeps things kewl if there's a hardware failure, but OS/400 spreads things around to make things fast.

Yes, I know that there's software RAID built into Mac OS X. :)
 

awrc

macrumors regular
Apr 20, 2002
215
1
Milwaukee, WI
Originally posted by bousozoku
I'm surprised that it's as slow as it is though. I expected much more speed considering what IBM did with HPFS when OS/2 jumped to 32-bit.
Well, bear in mind who's maintaining it these days :D

I'd like to see a Macintosh with enough hard drives to make fragmentation useful.

IBM's OS/400 spreads files across all the drive mechanisms so that any part of the file is equally close and can be quickly accessed. This is particularly useful for server systems such as IBM's iSeries (AS/400) where database access is 90 percent of what it does.
Well, databases are something of a special case, especially big databases. Combine that with the typical operational environment of a large database where you can have a large number of simultaneous queries, all potentially accessing different parts of tables, and all bets about data placement are off, since the drive heads are going to be all over the place anyway.

In circumstances like that, as you say, fragmentation can actually work to your advantage. I can't see it being hugely useful on a Mac though. Maybe an XServe with XRaid.

Maybe someone can answer this for me, storage systems have never been my specialty - do the current high-end RAID controllers do Really Clever Stuff like mainframe disk controllers (i.e. rescheduling pending disk requests to minimize head travel and rotational latency, thereby increasing throughput, etc)?
 

chmorley

macrumors 6502a
Jan 2, 2002
602
2
Denver, CO
Originally posted by sparkleytone
Drive 10 indeed does NOT defrag hard drives.
Yes, it does. Gotta keep up, man. ;)

The newest version (1.1) came out nearly a month ago. It is still $69, but it is a $40 upgrade for (registered) early adopters who bought the damn thing when it was nearly worthless. Yes, I'm a little bitter. I'll probably upgrade anyway.

Here's a screen shot of the defragger (from the Micromat website):
 

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MacMaster

macrumors 6502
Jul 17, 2002
387
1
That's one cool lookin defragger! But what's wrong with Norton Utilities? I don't have the X version so I boot into OS 9 to use it...:( It's good though!:)
 

chmorley

macrumors 6502a
Jan 2, 2002
602
2
Denver, CO
Originally posted by MacMaster
That's one cool lookin defragger! But what's wrong with Norton Utilities? I don't have the X version so I boot into OS 9 to use it...:( It's good though!:)
Yeah, even the OS X version can't defrag in OS X. It's what I use. And it's perfectly safe, but...

Not necessarily that there's anything wrong with it, but it doesn't optimize drives for OS X--it still puts OS 9 system files first, and classifies OS X system files as documents. As near as I can tell, the most important thing is that files are made contiguous. Given the speed of drives now, the physical placement of system files (or any files) probably doesn't make a huge difference.

Of course, the only way to know this for sure is to run benchmarks before and after defragging with Drive 10 v1.1. Does anyone have it yet?

Chris