SOLUTION FOUND: hot pb's, cpu=100%, crashes, etc.

[lkrfan77]

Hello Forum--

I previously posted in "Tiger eats 100% CPU" about a problem I had and that many other Tiger upgraders seem to be having. For some reason, I've noticed an especially large number posters with 12" PowerBooks having these problems, but that may just be a coincidence.

Basically, my problem was that my PB would crash at random times when there was a lot of system activity. Most notably was when I would try to Save documents/pics/etc. in Safari, that Safari would hang before the Save dialog opened. I felt that the culprit problem was a process called "Update" that I could see in Activity Monitor. After my computer was on for a short while, Update would take over CPU usage on my laptop. CPU usage would almost always be 100% w/ "Update" filling in the percentage that other apps/processes were not using.

As I said, this led to a number of crashes (3-4 a day...terribly annoying). I was afraid to use my computer for anything important, like schoolwork, because if I got going to fast for my computer (which I tend to do with computers), something would hang, especially Safari, and the whole system would come down.

I didn't think the problem was Spotlight...but I was wrong. After trying other things including the usual Permissions Repair (10s of times) and disk Repair, I decided to disable Spotlight. So, I entered Macintosh HD in the "privacy" tab in Spotlight. (Go to System Preferences | Spotlight pane | click the "+" to add a folder).

Thanks to the good people over at TUAW.com , I knew that this would basically delete Spotlight's index for my entire computer. I used my computer like this for about a day and it worked beautifully. As I said in the other post, I tried to crash my computer a number of times, but just couldn't. This is a good thing.

Last night, before going to bed, I decided to try re-indexing my hard drive. I deleted "Macintosh HD" from the Privacy tab in Spotlight and left my computer alone for the night. Althought it sounded like it was going to blow up as I drifted asleep, my Powerbook was doing fine in the morning. With a paper due today, I didn't have time to test until later..

Right now I am currently running 22 applications including some memory hog apps (Word, Camino, IE, iPhoto, GarageBand). The computer's holding up beautifully with none of the former problems I had.

So, if you're having strange crashes, if your computer's running hot all the time (mine's much cooler right now than it used to max out at), if you have a process called "Update" in Activity Monitor that's taken over your CPU processes, if Safari crashes a lot, if your computer gets lots of "spinning beachballs," or if you're just plain ready to downgrade to Panther, try this.

Allow Spotlight to reindex your hard drive. I cannot remember if I restarted my computer while it was doing the initial indexing, but it's a distinct possibility. The process "Update" seems to have to do a lot with writing to the disk, so maybe a corrupt index will cause your Mac to keep trying to update it.

I apologize for the long post and the double posting of information, but this was such an enormous problem for me that I feel a deserves to be seen by everyone.

P.S. My computer used to also not restart. It did when I disabled Spotlight. I have not tried to restart since I re-indexed last night, but I'll presume that it will restart smoothly now.
----------------
Please note:
SPECS
12" 1.33 ghz PowerBook
768 mb RAM
Tiger 10.4.1 running

[tapjpa]

Thanks for the great post, this seems to explain alot of the complaints I have seen in the forums here and elsewhere of "unexplained crashes, heat ect"

Jim

[ElDiabloConCaca]

Wonderful! Nice find!

I can just see it now... the standard reply here when someone gives too little information: "Did you repair your permissions? Repair the disk? Allow spotlight to reindex your drive?"

Add that one to the bag of generic troubleshooting goodies.

[Mikuro]

*grabs bag*
*adds tip*

Thanks for the informative post. I was under the impression "update" was for something besides Spotlight, because when Spotlight was indexing my drive, the CPU load was going to mdimport, not Update. In fact, I've yet to see Update use any significant amount of processing time at all (it's always visible in Activity Monitor, but it never uses more than 1% of my CPU).

Does anyone know exactly what the relationship is between mdimport and Update? Seems like they're both key parts of Spotlight, but they must be doing different tasks.

Edit: Just realized there was a man page for it. (Open Terminal, type "man update".) From the man page:

The update command helps protect the integrity of disk volumes by flush-
ing volatile cached filesystem data to disk at thirty second intervals.
Update uses the sync(2) function call to do the task. The normal_inter-
val and save_energy_interval can be used to set the sync(2) interval in
seconds of the normal case and the case where the computer is trying to
save energy.

So I guess update isn't dedicated to Spotlight exactly, but it clearly interacts with it (and in potentially nasty ways).

[lkrfan77]

Good find, Mikuro.

I'd also seen that the MD processes were supposed to be related to Spotlight. I refused to believe the process "Update" was related to Spotlight and thus I waited a long time before trying to mess with Spotlight as my PB's problem

As I guessed, my computer restarts like a charm now.

This seems like a major possible bug in Tiger, especially since it involves the Update process.

The update process, virtual memory, and spotlight may all be linked in some way. The update process flushes some cache on the computer..would this be RAM? So maybe if the Spotlight index has errors, Spotlight has trouble keeping it up to date in the background (while you use your computer). It uses a lot of RAM for this which is flushed to disk by the Update process. In turn, the Update process hogs your CPU and causes crashes.

The biggest problem I see with this idea is that the MDS processes did not seem to be using a lot of CPU while I was having problems. However, I am unsure of their RAM usage.

What do you think about my theory? I'm relatively new to Macs (Panther was my first OS X) and my "technical" knowledge of computers is limited, so pardon any major errors in wording or logic.

[Lt Major Burns]

i've been having genuine problems, similar to what you were saying, but alos nothing in common - i've never seen update at all, but tiger has just been buggy and unstable, spotlight has never been fast. nowhere near instant. in fact, panthers search was faster. i deducted that it was spotlight possibly causing the trouble when doing anything with smartfolders caused finder to use 100% cpu before crashing and relaunching. i was going to phone apple support (fun) but now i shall try your idea of resetting spotlight, although it would be the third time it will have indexed my drive, so i'm a little sceptical, to say the least. thank you!

[lkrfan77]

glad to possibly be of help, lieut.

Try running your computer for a day or 2 w/o Spotlight on...i.e. leave your HD in the Privacy pane so that there is no index.

Also, there's a fuller way to turn off Spotlight through the Terminal. Check macfixit.com, or tuaw.com