mysterious file/disk suck on my powerbook

I get disk I/O errors, which are the computer equivalent of coughing up blood; ominous.

They only happen with certain files. I notice it when syncing to my iPod or listening to music, for example. One music file will be a DEVIL FILE and cause the system to throw the I/O errors into the log after hanging up really badly (slow UI, processes crash, etc).

If I delete that one file then no problems for a while until another DEVIL FILE shows up.

I’m trying to figure out if maybe the iTunes-LAME script I use so I can use the LAME MP3 encoder might be contributing to this, or maybe LAME itself, but I can’t see how. Maybe something is messed up with 10.4.3?

18 thoughts on “mysterious file/disk suck on my powerbook

  1. It sounds to me like one or two physically bad blocks on your hard drive — you get a problem in a file, delete that file, and then see no more problems until another file decides to use those blocks. I actually don’t know of anything else that would cause something like what you’re seeing; software errors can cause I/O errors, but generally those would be disk-wide and pretty much fatal, the result of a configuration issue. I’ve never seen sporadic I/O errors be caused by anything other than physical disk degradation.
    I’m not sure how it works in OSX but I know in unix, fsck has a mark-bad-blocks thing, which goes through and tries to read/write every block on your disk, and tells the OS not to use any blocks that are bad.
    The only problem is what you mention in the first sentence — when a hard disk gets one bad block on it, IME it means that it’s going to start getting some more. It might not work out that way though — my general plan when I see stuff like this is to just mark the bad blocks as I see them and start thinking about buying new hardware, but only actually do so once the incidence rate starts really going up.
    Backups are a good idea too.


  2. What ^ he said. I used to get all kinds of I/O errors on my Linuux server, not enough to crash it or render it unuseable but when I tried to run certain programs it’d spit. Deleting those was a temporary fix that’d maybe buy me a month.
    Luckily it wasnt devastating to the point of inoperability so I was able to get everything but a very few files off it.
    Replacing the HDD cured it.


  3. I get disk I/O errors…
    Yes, ominous. These might be the result of filesystem damage that can be repaired with Disk Utility if you start up the computer with the Mac OS X installer disc. On the other hand, they might be the result of exhausting your the “bad sector” list in your hard disk with crashed media. Disk drives wear out. How old is yours?
    In the former case, I probably wouldn’t worry— especially if your startup volume isn’t formatted with HFS+ Journaling. The journaling filesystem seems better at avoiding the filesystem failures that result from poorly handled power interruptions. In the latter case, I’d get that puppy backed up and the drive replaced in a big fscking hurry (pardon the pun), before your Powerbook turns into an archeological investigation.


    1. What is this iTunes-LAME “script” you are using? Unless it runs with admin permissions and changes to root (which requires a password dialogue of some kind), I can’t see how it could reasonably be blamed for filesystem corruption.


      1. it’s an applescript + mp3 decoder binary
        i didn’t necessarily think it caused the problem, but so far all the issues have been with music files. also the problem occurred after a 10.4.3 update which makes me wonder if there’s some ugly subtle kernel or filesystem bug, ug.


    2. hfs_fsck in single user mode is clean. powerbook is almost new but a refurb. i have applecare so hardware replacement just requires fistfight at apple store. startup disk has HFS+ journaling. probably just going to back it up and take it in. mostly I dread their “you broke it” routine there lately and the fight-or-flight response I get when a couple of the dicks who work there decide to make me feel bad.


      1. Ouch. Show those to the AppleCare people. Looks like evidence of a serious hardware problem. AppleCare has a proprietary diagnostic suite that should let them see what’s wrong and fix it. They may want to take it to a lab for a few days, so be prepared to live without it for a few days. Or weeks, if the hardware gods hate you.


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