mds_stores, mds, and kernel_task i/o: SLOW computer

Question

mds_stores, mds, and kernel_task i/o: SLOW computer

My iMac is running very, VERY slowly and freezing a lot. Simple tasks like typing this, opening a tab in Chrome, taking a screenshot, and opening or closing a Finder window trigger a freeze and/or spinning rainbow wheel.

My CPU and RAM in use are very low. 18% of my hard disk is free. Energy impact is very low.

The only strange thing I can see in Activity Monitor is some large I/O spikes. Some things I don't understand such as mds, mds_stores, mds_worker, and kernel_task are writing many MB, sometimes GB of data, even when the only applications I have open are Finder and Chrome.

Dropbox, Google Drive, and CrashPlan aren't actively syncing. When I type something into Spotlight, I don't get a notification that it is indexing.

I've restarted the computer a couple of times. The first screenshot here was taken before the most recent hard restart, the following two afterward:

21.5-in late 2012 iMac 3.1 GHz Intel Core i7

OSX 10.10.5

Help??

Thanks!

iMac, OS X Yosemite (10.10.5)

Posted on Sep 17, 2015 4:52 PM

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Answer 1

Linc Davis

Level 10

209,739 points

Sep 17, 2015 8:43 PM in response to andbeonetraveler

When you see a beachball cursor or the slowness is especially bad, note the exact time: hour, minute, second.

These instructions must be carried out as an administrator. If you have only one user account, you are the administrator.

Launch the Console application in any of the following ways:

☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)

☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.

☞ Open LaunchPad and start typing the name.

The title of the Console window should be All Messages. If it isn't, select

SYSTEM LOG QUERIES ▹ All Messages

from the log list on the left. If you don't see that list, select

View ▹ Show Log List

from the menu bar at the top of the screen.

Each message in the log begins with the date and time when it was entered. Scroll back to the time you noted above.

Select the messages entered from then until the end of the episode, or until they start to repeat, whichever comes first.

Copy the messages to the Clipboard by pressing the key combination command-C. Paste into a reply to this message by pressing command-V.

The log contains a vast amount of information, almost all of it useless for solving any particular problem. When posting a log extract, be selective. A few dozen lines are almost always more than enough.

Please don't indiscriminately dump thousands of lines from the log into this discussion.

Please don't post screenshots of log messages—post the text.

Some private information, such as your name, may appear in the log. Anonymize before posting.

When you post the log extract, you might see an error message on the web page: "You have included content in your post that is not permitted," or "The message contains invalid characters." That's a bug in the forum software. Please post the text on Pastebin, then post a link here to the page you created.

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Answer 2

Sep 18, 2015 3:54 PM in response to Linc Davis

Here's one case:

9/18/15 6:48:51.000 PM kernel[0]: disk0s2: I/O error.

9/18/15 6:48:51.096 PM systemstatsd[448]: assertion failed: 14F27: systemstatsd + 3258 [934DD34F-EAF0-3DE6-B4A9-6DD998596D75]: 0xa

9/18/15 6:49:00.000 PM kernel[0]: disk0s2: I/O error.

9/18/15 6:49:17.000 PM kernel[0]: disk0s2: I/O error.

9/18/15 6:49:19.000 PM kernel[0]: disk0s2: I/O error.

9/18/15 6:49:19.244 PM systemstatsd[448]: assertion failed: 14F27: systemstatsd + 3297 [934DD34F-EAF0-3DE6-B4A9-6DD998596D75]: 0xa

9/18/15 6:49:20.374 PM com.apple.xpc.launchd[1]: (com.apple.appkit.xpc.sandboxedServiceRunner) The JoinExistingSession key is only available to Application services.

9/18/15 6:49:20.374 PM com.apple.xpc.launchd[1]: (com.apple.DataDetectorsDynamicData) The JoinExistingSession key is only available to Application services.

9/18/15 6:49:30.871 PM com.apple.xpc.launchd[1]: (org.ntp.ntpd) Unknown key for Boolean: ForceEnableHack

And another:

9/18/15 6:51:08.000 PM kernel[0]: disk0s2: I/O error.

9/18/15 6:51:08.140 PM systemstatsd[448]: assertion failed: 14F27: systemstatsd + 3258 [934DD34F-EAF0-3DE6-B4A9-6DD998596D75]: 0xa

9/18/15 6:51:50.000 PM kernel[0]: disk0s2: I/O error.

9/18/15 6:52:06.000 PM kernel[0]: disk0s2: I/O error.

9/18/15 6:52:08.000 PM kernel[0]: disk0s2: I/O error.

9/18/15 6:52:08.855 PM systemstatsd[448]: assertion failed: 14F27: systemstatsd + 3297 [934DD34F-EAF0-3DE6-B4A9-6DD998596D75]: 0xa

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Answer 3

Sep 18, 2015 3:57 PM in response to andbeonetraveler

Here's another one:

9/18/15 6:55:43.638 PM WindowServer[162]: disable_update_timeout: UI updates were forcibly disabled by application "Microsoft Excel" for over 1.00 seconds. Server has re-enabled them.

9/18/15 6:55:57.638 PM WindowServer[162]: disable_update_likely_unbalanced: UI updates still disabled by application "Microsoft Excel" after 15.00 seconds (server forcibly re-enabled them after 1.00 seconds). Likely an unbalanced disableUpdate call.

9/18/15 6:56:23.000 PM kernel[0]: disk0s2: I/O error.

9/18/15 6:56:23.161 PM systemstatsd[448]: assertion failed: 14F27: systemstatsd + 3258 [934DD34F-EAF0-3DE6-B4A9-6DD998596D75]: 0xa

9/18/15 6:56:23.823 PM Microsoft Excel[1871]: CGBitmapContextCreate: invalid data bytes/row: should be at least 5120 for 8 integer bits/component, 3 components, kCGImageAlphaNoneSkipFirst.

9/18/15 6:56:24.194 PM Microsoft Excel[1871]: CGBitmapContextCreate: invalid data bytes/row: should be at least 5120 for 8 integer bits/component, 3 components, kCGImageAlphaNoneSkipFirst.

9/18/15 6:56:24.327 PM WindowServer[162]: common_reenable_update: UI updates were finally reenabled by application "Microsoft Excel" after 41.69 seconds (server forcibly re-enabled them after 1.00 seconds)

I'll stop posting these now. Please let me know if you'd like more.

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Answer 4

Linc Davis

Level 10

209,739 points

Sep 18, 2015 4:06 PM in response to andbeonetraveler

The startup drive is failing, or there is some other internal hardware fault.

Back up all data on the drive immediately if you don't already have a current backup. There are ways to back up a computer that isn't fully functional—ask if you need guidance.

Make a "Genius" appointment at an Apple Store, or go to another authorized service provider.

If privacy is a concern, erase the data partition(s) with the option to write zeros* (do this only if you have at least two complete, independent backups, and you know how to restore to an empty drive from any of them.) Don’t erase the recovery partition, if present.

Keeping your confidential data secure during hardware repair

Apple also recommends that you deauthorize a device in the iTunes Store before having it serviced.

*An SSD doesn't need to be zeroed.

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Answer 5

Sep 18, 2015 4:14 PM in response to Linc Davis

Ugh. Ok, thanks for the info! I'll update if anything interesting happens.

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Answer 6

May 7, 2016 9:03 PM in response to Linc Davis

Yep, hard drive failure. It's working nicely now with a new SSD.

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