[X4U] Re: Defragmentation, was Cause of kernel panics

[Randy B.Singer]

Jon Warms said:

>> http://www.macattorney.com/ts.html
>> Item #5 and Note #2
>
>Use of a defragmentation  utility is a time-consuming, 

I don't think that it needs to be.  If you occasionally defragment your 
drive well before it reaches the 80% mark, subsequent defragmentation 
runs will go a lot quicker.

>and
>hazardous procedure. 

I think that this depends on the utility used.  It is, of course, always 
a good idea to have a complete backup before you use any hard drive 
manipulation utility, even something like Disk Warrior.

>Furthermore, its use masks the real
>underlying problem: careful hard drive management.

True.  Unfortunately not everyone is into really careful hard drive 
management, or they forgo it because of economic concerns.  (Even though 
good hard drive management might be more economical if followed 
religiously.)

>Randy's excellent Item 5 covers defragmentation extensively
>and informatively.

Thank you!

>He cites Apples guidance, but recommends periodic, though
>infrequent, defragmentation. Essentially, Randy cites a
>MicroMat technician and his own experience, saying that
>extreme fragmentation may prevent a drive from operating
>properly even at 80 percent of capacity.

Exactly.  MacFixIt and Intech have published things says the same thing.

>FIne, but the better fix is to either make more room or get
>a larger drive.

Making room by itself may not fix the fragmentation problem.

Getting a larger drive is a good idea, but not an economical one.  And 
though a new drive may only run a couple hundred dollars (and, 
personally, I don't think that a couple hundred dollars is a small sum of 
money) a lot of folks don't have that to spare, especially after sinking 
thousands into an entire computer system.

>I've lost data using optimization utilities. Defragmenters
>perform radical surgery on your file system in the goal of making
>it better. Any interruption or anomaly in the process and your
>data is shredded. I won't take the chance any more.

I can't argue with your personal experience.  I'm always shy myself about 
doing something if I've been burned before.

On the other hand, in the past couple of decades I've never lost data to 
a defragmentation program, and I can't recall hearing from anyone other 
than yourself who has.

I do recall one hot summer when I ran SpeedDisk and there were three 
separate blackouts during the run.  Each time I restarted SpeedDisk and 
it too up right where it left off and I didn't lose a bit of data.  Very 
impressive.  (On the other hand, I haven't been without a UPS since that 
episode.)

I think that good defragmentation software is careful to make sure that 
you won't lose data in the event of an interruption.  (But that is a good 
question to ask about the new utility iDefrag.  I'll have to ask them 
when I get a chance.)

>Also, defragmentation is slow - very slow. If the
>the drive has only 20 percent or less of free space, there isn't
>much room for the defragmenter to work. It takes a long time.

Once again, this is a good reason to start regularly defragging well 
before the 80% point.  (I can even see how defragging for the first time 
with a hard drive over 80% full, could have been the reason that you has 
your disastrous experience with defragmentation software.)

I think that the possibility of directory damage with a drive that is 
over 80% full and undefragged is a greater danger than using a 
defragementation utility.
But I agree that using any hard drive repair utility involves some risk.




Randy B. Singer
Co-Author of: The Macintosh Bible (4th, 5th and 6th editions)

Routine OS X Maintenance and Generic Troubleshooting
http://www.macattorney.com/ts.html