Since upgrade to macOS 12.6.1, mds process is running non-stop

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Since upgrade to macOS 12.6.1, mds process is running non-stop

Yesterday I upgraded my M1 MacBookPro to macOS 12.6.1. Ever since then, the external drive I use for Time Machine backups has been grinding away, and ActivityMonitor shows that the mds process and several mdworker_shared processes consuming a high percentage of the CPU cycles. I believe this means that the OS is running Spotlight indexing on the drive. This is taking way longer than I would expect (20 hours at this point) for a 4-TB drive (which has 3.2 TB available). I'm concerned that something is broken, but I don't know what to do about it.

I tried rebooting the Mac, but the processes resumed after the reboot. I also tried adding the drive to the "Prevent Spotlight from searching these locations" list in Spotlight Preferences, but it wouldn't allow adding a "Time Machine backup folder" to the privacy list.

Any suggestions for what else to try or whether I should even be concerned?

MacBook Pro 16″, macOS 11.5

Posted on Nov 2, 2022 9:47 AM

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Answer 1

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Camelot

Level 9

58,173 points

Nov 2, 2022 9:52 AM in response to dsamb

> Any suggestions for what else to try

Wait.

Seriously.

mds is the part of the spotlight metadata service which indexes every file on disk so you can search, filter, etc.

One of the first things that happens when you upgrade the OS, is that the old metadata index is thrown away and a new one is created. That takes time. Ranging from a few hours to several days, depending on the size of attached disks and number of files.

So at this point the best action is to just let it run - it will ultimately catch up and sit quietly in the background. It's just a heavy lift in the early days.

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Answer 2

Camelot

Level 9

58,173 points

Nov 2, 2022 10:36 AM in response to dsamb

It might be a little odd with a point-upgrade on the OS - it's certainly normal between major releases, and I assumed that was the case.

Even so, give it a little time to see if it quiesces. If it doesn't we can dig in a little deeper.

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Answer 3

dsamb Author

Level 1

4 points

Nov 3, 2022 8:41 AM in response to Camelot

I finally gave up on it late last night after ~34 hours of churning away. This is certainly not normal behavior. I'm wondering if it could be because of a damaged hard drive...

Back in September Time Machine refused to back up to this drive and after consulting with the drive vendor's tech support staff who helped me diagnosed the problem as a bad volume directory, I erased the drive and started using as a "fresh" Time Machine volume. Yesterday I tried running Disk Utility's Repair function on the drive, and it immediately failed with a message saying something about not mounting the disk (it was mounted). I don't know if that error was due to the fact that mds was thrashing the disk, or an inherent problem with the drive. Last night I ran an mdutil scan with this result:

mdutil -s -a -v

/:

Indexing enabled.

/System/Volumes/Data:

Indexing enabled.

Scan base time: 2022-11-02 14:42:36 +0000 (52155 seconds ago), reasoning: '(null)'

/Volumes/Backup:

Indexing enabled.

Scan base time: 1970-01-01 00:00:01 +0000 (1667452310 seconds ago), reasoning: '(null)'

I don't know how to interpret that result, but I'm guessing that the scan base time on Backup (the drive in question) is bad news.

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Answer 4

dsamb Author

Level 1

4 points

Nov 2, 2022 10:00 AM in response to Camelot

I'll wait then.

I should have added that I updated from 12.6 to 12.6.1. I have never experienced this sort of thing with any previous OS update. The fact that it's coming after a minor update is particularly suspicious.

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Since upgrade to macOS 12.6.1, mds process is running non-stop

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