mds – what MDS process is and why it uses CPU on the Mac

And mds is short for metadata server. They are processes used by Spotlight to index your Mac. So, for example, if you copied lots of data to your Mac from somewhere else, you would notice mds and mdworker running in Activity Monitor.

Random macOS BATTERY DRAIN and POWER DRAW FIXED – mds_stores task

How long does mds & Spotlight take to finish indexing?

How long it takes to update the Spotlight index depends on a few variables, but mostly the size of your hard drive, the amount of data being indexed, major changes to the filesystem, and the time since last indexing. Just let the indexing complete, it generally takes between 15 and 45 minutes to complete.

If Spotlight isn’t working, you can check out these Spotlight troubleshooting tips which will get you situated again. If you don’t ever use the search feature or just don’t like it, you can also disable Spotlight and all of its indexing.

mds process mac

What Are mds and mdworker, and Why Are They Running on My Mac?

If you’ve recently migrated your files and apps from one Mac to another, it’s normal for mds and mdworker to take up a great deal of CPU power and memory. The same goes if you recently added a bunch of new files to your computer. The processes are both working to build an index of all your files, which is what will later power your fast searches.

The two processes are part of Spotlight, the macOS search tool. The first, mds, stands for metadata server. This process manages the index used to give you quick search results. The second, mdworker, stands for metadata server worker. This does the hard work of actually indexing your files to make that quick searching possible.

Either way, your entire Spotlight index will be re-built, which again you can see by pulling up Spotlight and looking for the word “Indexing” at top left, alongside the progress bar. Once that process is done, mds and mdworker should stop taking up excessive CPU. If not, consider running First Aid to fix file system problems on your Mac, then re-building the index again. That will solve the problem in almost all instances.

Spotlight is configured to not use up all your resources. If you’re doing something that’s processor intensive, these processes should back off. But if your Mac is left idle, and you’re not on battery power, Spotlight will feel free to use whatever resources are necessarily in order to build the database.

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