SLOW ibook, HD working all the time, need diagnosis !

Question

Hello !
I need comments and thoughts. I experience problems that might relate to this thread : (ie hard drive failure, than replacement) http://discussions.apple.com/thread.jspa?threadID=1045960&tstart=75
Symptoms begun lightly, thant increased so i cannot identify one cause. The ibook is now just impossible to work with, for example, booting can take 10 to 20 min, opening an app can take two or three min, and there are delays for real simple actions (opening a folder, closing a window, scrolling in the dock...). everything takes time, delays, freezes and spinning beachball.
Meanwhile, once i openened and work with in an application (Word for ex), it's ok.
The HD makes noises just like it's working all the time, swapping files, or just as if i had a great resource consuming task in the background. I'm not skilled enough to read Activity Monitor for the disk usage, but the CPU and RAM both look ok.
Of course, i thought the HD's in trouble so here's what i remember having done yet :
• Maintenance scripts, repair permissions (very long), zapping PRAM, PMU, etc... usual stuff, many times
• Fsck or "repair disk" are long, but don't tell any problem ; SMART status is verified, free space on the disk is almots 20 Go
• Running tech tool deluxe, from "apple protection plan" wich sees nothing
• Archive and install (problems still here even if slightly better for some time)
• Clean install with total HD erase (same comment)
• Boot without Ram and airport card
That's where i'm at. I have two questions :
• Would it be good to get Apple Hardware Test (my version is too old), and running it in loop mode ? what about diskwarrior ?
• Could it be something else than a hard drive problem ?
Thanks a lot for your help and clues !
ps : anyway, i'm getting to the idea that i have to buy a new book. Also, i think i'll give up buying second-hand macs, from now on
cheers
Ben

Answer 1

Benjamin,
*Check your console messages.*
One contributing problem I've noticed is the growth of operating systems as we patch them. Mine loads quickly, but desktop operations have a 5 to 10 second response time. It loads quickly because the 5 GB free is contiguous, offering plenty of room for swap files, usually about 5 Mb each. Its response time is presumably slow because it is swapping processes rather than paging.
I don't know at what amount of free space MacOSX switches from efficient paging to disk to slow swapping of whole processes to disk. However, it's unlikely you have 20 GB of free space.
When I once had 7.5 GB of free space, the computer stopped. The console told me I hadn't sufficient contiguous freespace to create a new 5 MB (MB not GB!) swap file. (Swap files have to be contiguous.) Your computer may be swapping rather than paging. This I can easily imagine if you upgraded operating systems by modifying the previous (as Apple suggests), and applied all its patches (needed for security). Apple warns this will happen if you create & delete movies.
Booting shouldn't take 10 or 20 minutes on a damaged hard drive, it should stop at the first sign of damage. I can probably imagine it taking that long reading files whose pieces are scattered, and executing startup and OS files that need a large amount of virtual memory.
It's likely that Word, made by Microsoft, violates acceptable civil behavior and takes excessive real memory, minimizing disk swapping.
What is puzzling is the
• Clean install with total HD erase (same comment).
That should have cured any disk fragmentation, unless it was a fast backup and restore of a disk image, which doesn't defragment files as it reads & writes them.
Here's how to check for excessive disk fragmentation:
1. Open /Applications/Utilities/Console and read its messages;
2. Open /Utilties/Disk Monitor and examine the Disk Activity graph for a while.
a. If it spikes regularly, it's likely a background application of your doesn't respect your power saver. Remove these one-by-one to find the problem one & write the company. You want your drive to sleep when possible.
b. To the point, if the curve stays near the top all the time, the virtual memory of ordinary programs, which should normally happily stay put in 20 GB of space are all competing for the contiguous spaces between tiny files. This is like a children's game we play, called 'musical chairs'.
Further, the memory manager is running full speed (using CPU time and real memory, exacerbating the problem). When more time is spent looking for space for swap files than writing them, we say the disk is 'thrashing'. The disk then makes the sound yours does, and the computer does almost nothing useful.
c. Just an idea, but 'Disk Utility' lets you create 'disk images', empy files of any size you request. (I may have modified mine to do this.) If your disk is severely fragmented, the maximum size file you can create may be small. This is just a sufficient condition for fragmentation, not a necessary one.
d. Install this in Utilities and run it:
http://www.versiontracker.com/dyn/moreinfo/macosx/27329
It measures the degree of file fragmentation on any drive.
*Possible Solution*
If excessive fragmentation is the problem, various commercial utilities will defragment your drive. However, I never use commercial utilities, so I run the shareware iDefrag.
http://www.versiontracker.com/dyn/moreinfo/macosx/25411
This is now US$ 30. Though you can run an algorithm that would fix excessive fragmentation from the boot disk, it's normal to install it on a CD (which they provide a program for). If you install it on your second computer as well, so you can place yours in Target Disk Mode, threats appear that give 'termination' a new meaning.
Others will tell you that the advanced HFS+ filesystem doesn't need defragmenting. It is true that on a G3 iBook, defragmenting files and optimizing their order will not speed up the machine if it has many, large, unfragmented freespaces: the speed bottleneck is elsewhere. (It will greatly speed a G4 Mac.) However, defragmentation is eventually necessary to create these freespaces.
Bruce