Mdworker process - mac is very very slow, apps not responding

the Mac Pro was very slow at doing most things, lots of beach balls and applications not responding.

How much free drive space on the Mac?

Right or control click the MacintoshHD icon. Click Get Info. In the Get Info window you will see Capacity and Available. Make sure there's a minimum of 15% free disk space.

You can stop Spotlight from indexing > Spotlight tips

Have you emptied the Safari cache lately? From your Safari menu bar click Safari > Empty Cache. Quit then relaunch Safari to test.

If that didn't help, back to the menu bar, click Safari > Reset Safari. Select the top 5 boxes, click Reset. Try Safari.

And try troubleshooting the Safari .plist file (preferences)

Go to ~/Library/Preferences

Move the com.apple.Safari.plist file from the Preferences folder to the Desktop.

Quit, relaunch Safari to test.

If that helped, move the .plist file to the Trash, If not, just move it back to the Preferences folder.

And try troubleshooting Safari third party plugins. Go to Safari > Preferences then select the Security tab. Deslect: Enable plug-ins

Quit then relaunch Safari to test. If that made a difference, then you need to find the plugin(s) causing the problem > Unsupported third-party add-ons may cause Safari to unexpectedly quit or have performance issues

You need to free up drive space so the system runs faster.

Freeing space on your Mac OS X startup disk

OSX Tips Where did my Disk Space go?

I have a bootable back up which is mirrored to the main system drive, the capacity of that is 1TB. I'm thinking of using that as the main system drive, though right now I'm not to sure how to go about it.

Better to get one drive fixed first.

ekaton wrote:

I've seen 100%of CPU use though mdworker.

Mdworker is the metadata server worker, ie, it scans and indexes files as needed. So it would seem you have a Spotlight issue.

My main system drive, is 500GB capacity with about 80GBs free. 15% of 500 is 75, so I'm really pushing it on capacity.

Nonsense. The "15%" (or whatever figure) is an urban myth. 80GB free is plenty; you may have an issue if you write lots (I do mean lots) of DVDs, or with large temp files of pro apps like Logic.

The first thing to do is check your disk(s) for errors. Use Disk Utility > Verify Disk (not Verify Disk Permissions). Next, temporarily remove any plugins in <~/Library/Spotlight> and </Library/Spotlight>, especially if they came with the software you installed lately.

Then delete Spotlight indices and re-index your volumes overnight, letting the indexing process run until completed. See

<http://support.apple.com/kb/HT2409>

<http://www.thexlab.com/faqs/stopspotlightindex.html>

I have just experienced the same issue (critically slow response on mac and mdworker using 60 - 85% of CPU with mds using over 40% at the same time - even with 16 cores) - with over 1.7 TB of free space on system drive. Seems that spotlight does not let me know anymore (upgraded to Mountain Lion an hour ago) that spotlight is indexing. That was a useful message to know when the computer was slowing down. Not sure when that feature was pulled, or if spotlight is not telling me it is indexing for some other reason, but now that it seems this is indeed indexing I will leave overnight and see if it comes good in the morning. Hope this insight helps someone.

it does let you know if you click on the spotlight icon