The mds_stores process can use a large amount of CPU while macOS indexes files for Spotlight. Usually, the activity stops after indexing finishes. If it continues for hours, repeatedly returns, or makes your Mac hot and slow, you can reduce the load by checking Spotlight status, allowing indexing to finish, removing problematic locations from search, or rebuilding the Spotlight index.
Quick Answer
To stop mds_stores from causing high CPU usage:
- Open Spotlight settings and check whether macOS is still indexing.
- Give indexing time to finish, especially after a macOS update, migration, or large file transfer.
- Restart your Mac and disconnect external drives temporarily.
- Add problematic folders or drives to Spotlight Privacy.
- If the problem continues, rebuild the Spotlight index in Terminal.
Do not force-quit mds_stores. It is a system process, and macOS normally restarts it when needed.
What Is mds_stores?
mds_stores is part of Spotlight, macOS’s built-in search and indexing system. It scans files and stores information about their names, contents, locations, and metadata so that searches can return results quickly.
High CPU usage from mds_stores is often normal when macOS is:
- Indexing a new Mac
- Processing a macOS update
- Restoring files from a backup
- Copying a large number of files
- Connecting an external drive
- Rebuilding the Spotlight index
- Finding and reprocessing files that repeatedly change
You can see the process in Activity Monitor. Short periods of high usage are usually not a problem. The issue is more significant when CPU usage remains high for an extended period and causes noticeable heat, fan noise, battery drain, or sluggish performance.
Check Whether Spotlight Is Still Indexing
Before changing settings, check whether indexing is active. Interrupting a normal indexing task can make it take longer.
- Click the Spotlight icon in the menu bar, or press Command-Space.
- Search for a file or a simple word.
- If Spotlight displays a message such as Indexing, wait for the process to finish.
- Keep your Mac connected to power if it is a MacBook and avoid repeatedly restarting it during this process.
You can also check Activity Monitor:
- Open Activity Monitor from Applications > Utilities.
- Click the CPU tab.
- Select
mds_storesin the list. - Look at its CPU usage and observe whether it gradually decreases.
If the percentage falls over time, indexing may be progressing normally. If it remains high indefinitely, continue with the steps below.
Restart Your Mac and Disconnect External Drives
A restart can clear a temporary indexing problem. External storage can also trigger repeated indexing, especially when it contains many files, backup data, virtual machines, or an unsupported or damaged file system.
Before restarting, save your work and close open apps. A restart closes all applications and can cause unsaved changes to be lost.
- Click the Apple menu in the menu bar.
- Choose Restart.
- After your Mac starts, wait several minutes and check Activity Monitor again.
- If an external drive is connected, eject it from Finder before reconnecting it.
To eject a drive:
- Open Finder.
- Find the drive in the Finder sidebar under Locations.
- Click the Eject button next to it.
- If Finder says the drive is in use, close files and apps that may be accessing it before trying again.
If mds_stores becomes active only after a particular drive is connected, that drive or its contents may be causing repeated indexing.
Add a Problematic Location to Spotlight Privacy
You can prevent Spotlight from indexing a folder or drive by adding it to the Spotlight Privacy list. This is useful for locations containing large archives, backup files, virtual machines, development data, or files you never search.
Adding a location removes it from Spotlight search results. Make sure that limitation is acceptable before continuing.
- Open the Apple menu and choose System Settings.
- Click Spotlight in the sidebar.
- Click Spotlight Privacy.
- Click the Add button, which may appear as a plus sign.
- Select the folder or drive that you want to exclude.
- Click Choose or Done, depending on the screen shown.
On some macOS versions, you can also drag a folder or drive into the Spotlight Privacy list.
After adding the location, macOS should stop indexing it. CPU usage may remain elevated briefly while the change takes effect.
What Should You Exclude?
Common candidates include:
- Large backup volumes
- Virtual machine folders
- Temporary export folders
- Download archives that you do not search
- External drives containing media libraries
- Folders with constantly changing build or cache files
Do not exclude your entire startup disk unless you have a specific reason. Doing so can make Spotlight search much less useful and may affect features that depend on indexing.
Remove and Re-add a Location to Trigger Reindexing
If a specific folder or drive appears to be indexed incorrectly, removing it from Spotlight Privacy and adding it again can trigger a fresh index.
This process changes Spotlight’s index for that location. It should not delete the files themselves, but avoid changing settings while important work is in progress.
- Open System Settings.
- Select Spotlight.
- Open Spotlight Privacy.
- Select the affected folder or drive.
- Click the Remove button, usually shown as a minus sign.
- Wait a moment, then add the same location again.
- Allow macOS time to rebuild the index.
If the location is an external drive, eject it first and reconnect it only after the privacy-list change if necessary.
Rebuild the Spotlight Index in Terminal
If Spotlight appears stuck and mds_stores continues using high CPU, rebuilding the index can resolve a damaged or incomplete index. The process may temporarily increase CPU usage because macOS must scan files again.
The following command changes Spotlight’s indexing state for the startup volume. It does not delete your personal files, but it will remove and recreate Spotlight’s search index. Save your work before running it.
- Open Terminal from Applications > Utilities.
- Enter this command:
sudo mdutil -E /
- Press Return.
- Enter your administrator password when prompted. Terminal does not display the password as you type.
- Press Return.
- Leave the Mac connected to power and allow indexing to finish.
The sudo command runs the operation with administrator privileges. mdutil manages Spotlight indexing, and -E erases the existing index so macOS can rebuild it. The slash (/) specifies the startup volume.
You can check the indexing status with:
mdutil -s /
This reports whether indexing is enabled for the startup volume. To see more detailed status, use:
mdutil -a -s
This checks all mounted volumes.
Temporarily Disable Spotlight Indexing
If you need to stop indexing temporarily while diagnosing the problem, you can disable it for the startup volume:
sudo mdutil -i off /
This prevents Spotlight from creating or updating the index on that volume. Spotlight searches may return incomplete or no results, and some macOS features may be affected.
To turn indexing back on, run:
sudo mdutil -i on /
Then rebuild the index if needed:
sudo mdutil -E /
Do not leave indexing disabled permanently unless you understand the effects. Re-enabling it is the safer long-term choice for most users.
Check for Files That Keep Changing
Some files cause Spotlight to work repeatedly because they are constantly updated. Examples include:
- Virtual machine disk images
- Application caches
- Log files
- Large databases
- Synchronization folders
- Developer build directories
- Backup or media-management libraries
If you recently installed an app or started using a new storage service, consider whether it creates or changes thousands of files. You can exclude only the relevant folder through Spotlight Privacy instead of disabling indexing for the entire Mac.
If the files are part of a cloud-sync service, allow the service to finish syncing before rebuilding Spotlight. Otherwise, the index may be rebuilt while files are still changing, causing additional CPU usage.
Troubleshooting Persistent High CPU Usage
mds_stores remains high after a rebuild
A rebuild can temporarily make CPU usage higher. Wait until indexing has had time to complete, then check Activity Monitor again. If usage remains high, inspect external drives and recently added folders.
If one location is clearly responsible, add it to Spotlight Privacy and observe whether the problem improves.
Spotlight search does not find files
Confirm that Spotlight indexing is enabled:
mdutil -s /
If indexing is disabled, enable it:
sudo mdutil -i on /
Then rebuild the index:
sudo mdutil -E /
Also check System Settings > Spotlight > Spotlight Privacy. A folder on that list will not appear in normal Spotlight results.
CPU usage returns after every restart
Repeated high usage may indicate that macOS is reindexing a drive each time it is mounted, or that files are continuously changing. Disconnect external drives one at a time to identify a possible source. You can also add a suspected folder or drive to Spotlight Privacy.
If the issue began after a drive started showing errors, copy important files to another location and check the drive using Disk Utility. Do not erase or reformat the drive unless you have a complete backup and understand that erasing removes its contents.
The Mac is hot, slow, or draining its battery
High CPU usage naturally increases heat and power consumption. Close unnecessary apps, disconnect devices you do not need, and connect a MacBook to power while indexing completes.
Avoid placing a MacBook on a soft surface that blocks ventilation. If the fans remain loud after Spotlight activity stops, check Activity Monitor for another process using CPU.
mds_stores is not the only process using high CPU
Spotlight may not be the underlying cause. In Activity Monitor, sort the CPU column and look for apps that are repeatedly changing files, such as backup tools, synchronization services, media applications, or virtual machines.
Quit only apps that you recognize, and save your work first. Do not remove system files or terminate processes at random.
When to Contact Apple Support
Seek additional help if:
- The Mac remains extremely slow after indexing finishes
- The problem occurs with no external drives connected
- Disk Utility reports storage errors
- Files disappear, fail to open, or become corrupted
- The Mac repeatedly restarts or shuts down
- High CPU usage continues after a clean Spotlight rebuild
Before contacting support, note when the problem began, whether it affects a particular drive, and which troubleshooting steps you have already tried. A current backup is especially important if storage errors or unusual file behavior are involved.
Frequently Asked Questions
Is it safe to quit mds_stores?
It is better not to force-quit mds_stores. macOS manages the process and may restart it immediately. If indexing is the cause of high CPU usage, address the indexed locations or rebuild the index instead.
How long should mds_stores use high CPU?
The duration depends on the number of files, drive speed, recent system changes, and external storage. A short period is normal after many files change. If usage does not decline after indexing should reasonably be complete, investigate the source.
Will rebuilding Spotlight delete my files?
No. Rebuilding the Spotlight index removes the search database and creates it again. It does not intentionally delete personal files. However, save your work before using Terminal commands and maintain a backup of important data.
Can I disable Spotlight permanently?
You can disable indexing, but doing so makes Spotlight searches incomplete and may affect features that depend on the index. For most users, excluding only a problematic folder or drive is a better solution.
Why does mds_stores use CPU after connecting an external drive?
macOS may need to index the drive’s contents. Drives with many files, frequently changing data, or file-system problems can cause longer or repeated indexing. Eject the drive, test the Mac without it, and add it to Spotlight Privacy if you do not need its contents searchable.
Final Thoughts
mds_stores is usually busy because Spotlight is indexing files, not because the process itself is malfunctioning. Start by checking whether indexing is progressing, then restart the Mac and test external drives. If the activity persists, exclude the responsible location or rebuild the Spotlight index with mdutil. Re-enable indexing after temporary testing so Spotlight and related macOS features continue working normally.