Log shows "disk0s2: I/O error"

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Log shows "disk0s2: I/O error"

Hello all,

I have been having some trouble, specifically related to iTunes 8 (see my other posts). Digging around my log, I've noticed the following message appear every time (and several times) during artwork-related freezes. "kernel[0]: disk0s2: I/O error."

I'm quite new to OSX and its log, but to me this sounds like a severe hardware error. I've not found many other referrals to this error code using Google and searching this site. Is this a Hard Drive failure waiting to happen or is there hope that this is a 10.5.5/iTunes 8.0.x problem? I've especially noticed the freezing errors since either of the two, a reinstall hasn't helped much. It's only now that I've examined my logs, but as the symptoms are the same, I assume it was this I/O error all along.

I hope someone can enlighten me, and hopefully reassure me.

Best regards,

Loek

iMac 20" 2.4GHz, Mac OS X (10.5.5), 3GB RAM

Posted on Oct 26, 2008 6:52 AM

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Answer 1

lwkeizer Author

Level 1

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Oct 30, 2008 12:50 PM in response to lwkeizer

Hello again,

No one has any experience in this matter? I'd rather hear if this is the result of recent updates (Security, 10.5.5, iTunes 8, whatever) than a hardware issue, as the latter will cost me a lot of time and money to solve. Is this code specifically hardware-related, or can it be a problem with software causing these I/O errors as well? Does anyone have a list of these codes?

Best regards,

Loek

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Answer 2

knussear

Level 1

8 points

Oct 31, 2008 3:44 PM in response to lwkeizer

I'm having the same problem. I replaced the drive and pulled my data back in from a backup but I still have corrupted files. Restoring from an older backup seems to fix things. Not sure what munched the files, but my disk did suddenly lose its partition map before I replaced it.

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Answer 3

lwkeizer Author

Level 1

0 points

Nov 8, 2008 3:34 AM in response to lwkeizer

Hello again,

Does anyone know anything about these I/O errors? There is precious little documentation on the issue. I noticed that my iMac started hanging (with the logged I/O errors) when accessing my homepage. Clearing the cached files helped for a bit. It seems that the Mac is writing away files incorrectly. Hard Drive issue? Controller issue? Software issue? I've ran all OSX hard disk and system check ups, booting from CD it seems to pass with flying colours. Any final thoughts before I pack it up and take it to get the HDD replaced? I'm a bit peeved that after 10 years without HDD issues in my PCs my first Mac ships with faulty hardware (or even worse: destructive updates).

Best regards and thanks in advance,

Loek

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Answer 4

roam

Level 6

13,631 points

Nov 8, 2008 4:13 AM in response to lwkeizer

Try running Disk Repair from Disk Utility to get more information if there is a problem with the disk.
There may not be, or it may correct the error if it can.

To do this: Insert the Install Disk 1 into the drive and then select Restart; when you hear the chime hold down C key until the apple logo appears.
This will take you to the installation software, but you do not want to install.
Select your language, then go up to the top menu bar to Utilities and navigate to the Disk Utility application.
Select the start up drive, then go to the First Aid pane where you can click on Repair Disk.
If it finds errors, repeat the process until it reports no errors.
After these repairs, quit the Installer, and restart normally.

Once restarted normally run Repair Permissions from the Disk Utility application found on your hard drive in Application/Utilities.

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Answer 5

lwkeizer Author

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Nov 8, 2008 4:23 AM in response to roam

Thanks for your help, although as I indicated I've ran all Disk Repairs/Extended Hardware Checks from the CD. Nothing shows up. I don't think the problem is that easy to detect with a simple probe, and that it's a more structural problem. Thanks again for your reply, I appreciate it.

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Answer 6

Nov 8, 2008 9:08 AM in response to lwkeizer

HI--

Your disk I/O errors indicate a problem with the drive. Since it seems to be related top specific files and programs, I'd guess that you have a bad block or blocks on the hard drive.

To fix them, what you'd need to do is to re-format the hard drive (make sure you back up all your data first) and, when choosing options, make sure you tell Disk Utility to "Zero out data". That forces the drive to write to every block on the disk, and if a block is bad, it will get remapped to one of the spares the disk keeps for just those situations. This process will take a long time, depending on how big the drive is, it could take a few hours.

Once you've re=formatted, you'll need to re-install the OS and bring back your files. But before you take the time to do all that, make sure you check the S.M.A.R.T. status of your drive after the re-format is complete. If there are too many bad blocks, the drive will run out of spares and the status will be "failing". If that's the case, then you'll need a new drive.

Of course, if your computer is still under warranty, then you might want to just take it in for a new drive.

charlie

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Answer 7

lwkeizer Author

Level 1

0 points

Nov 9, 2008 3:44 AM in response to Charles Minow

Hi Charlie,

Thanks for your advice, I hadn't tried your suggestions yet. They seem like the concrete measures I need before push comes to shove and I take it in.

Just one thing, however. If you could tell me where I can find the "S.M.A.R.T." status of the drive, I can get started on that.

Thanks again,

Loek

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Answer 8

GaryFL1

Level 1

29 points

Nov 9, 2008 5:05 AM in response to lwkeizer

The SMART status will be shown within the Disk Utility at the bottom right after you have verified or attempted to "repair"

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Answer 9

lwkeizer Author

Level 1

0 points

Nov 9, 2008 7:02 AM in response to GaryFL1

Thanks all, that's all useful stuff. The appearance of bad blocks makes sense with my story.

I'll pop by the local service center tomorrow, and ask if they'd prefer my Mac with the logs intact (and what kind of costs are attached), or if I should give a thorough reformatting a go beforehand.

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Answer 10

Nov 9, 2008 8:30 AM in response to lwkeizer

Hi--

lwkeizer wrote:
Just one thing, however. If you could tell me where I can find the "S.M.A.R.T." status of the drive, I can get started on that.

Where gaurora said, in the Disk Utility.

Keep in mind, though, that S.M.A.R.T. status can be a bit of a lie if it says your drive is "verified". There are certain thresholds that have to be reached before the status will change to "failing". Once the status is "failing", though, it's best to believe it.

charlie

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