I have a recording studio, and therefore don't want my Time Machine drive being accessed all the time since it's very noisy. I use TimeMachineEditor to schedule backups during the night, which works well. I don't have Mac's automatic backups enabled.

Now, most of the day, it seems the 'mds' process is accessing my Time Machine drive, but I can see that Time Machine is not actually backing up. Why is this occurring? How do I stop this from happening?

Here's an example of my lsof log:

mds_store   354                   root  145u      REG               1,37         28                  26 /Volumes/Time Machine/.Spotlight-V100/Store-V2/F2A3B1DA-3027-4BE7-BD74-8E26C5D499AF/indexState
mds_store   354                   root  199u      REG               1,37  237654016                  53 /Volumes/Time Machine/.Spotlight-V100/Store-V2/F2A3B1DA-3027-4BE7-BD74-8E26C5D499AF/.store.db
mds_store   354                   root  201u      REG               1,37   33554432             3169285 /Volumes/Time Machine/.Spotlight-V100/Store-V2/F2A3B1DA-3027-4BE7-BD74-8E26C5D499AF/live.4.indexPostings
mds_store   354                   root  202u      REG               1,37   33554432             3169285 /Volumes/Time Machine/.Spotlight-V100/Store-V2/F2A3B1DA-3027-4BE7-BD74-8E26C5D499AF/live.4.indexPostings
mds_store   354                   root  209u      REG               1,37   16777216             3169286 /Volumes/Time Machine/.Spotlight-V100/Store-V2/F2A3B1DA-3027-4BE7-BD74-8E26C5D499AF/live.4.indexTermIds
mds_store   354                   root  210u      REG               1,37   67108864             3169287 /Volumes/Time Machine/.Spotlight-V100/Store-V2/F2A3B1DA-3027-4BE7-BD74-8E26C5D499AF/live.4.indexPositions
mds_store   354                   root  230u      REG               1,37   16777216             3169288 /Volumes/Time Machine/.Spotlight-V100/Store-V2/F2A3B1DA-3027-4BE7-BD74-8E26C5D499AF/live.4.indexPositionTable
mds_store   354                   root  231u      REG               1,37     131584             3169289 /Volumes/Time Machine/.Spotlight-V100/Store-V2/F2A3B1DA-3027-4BE7-BD74-8E26C5D499AF/live.4.indexDirectory
mds_store   354                   root  249u      REG               1,37      65536             3169290 /Volumes/Time Machine/.Spotlight-V100/Store-V2/F2A3B1DA-3027-4BE7-BD74-8E26C5D499AF/live.4.indexCompactDirectory
mds_store   354                   root  250u      REG               1,37   50331648             3169291 /Volumes/Time Machine/.Spotlight-V100/Store-V2/F2A3B1DA-3027-4BE7-BD74-8E26C5D499AF/live.4.indexArrays
mds_store   354                   root  252u      REG               1,37  237654016                  52 /Volumes/Time Machine/.Spotlight-V100/Store-V2/F2A3B1DA-3027-4BE7-BD74-8E26C5D499AF/store.db
mds_store   354                   root  254u      REG               1,37       4096             3169281 /Volumes/Time Machine/.Spotlight-V100/Store-V2/F2A3B1DA-3027-4BE7-BD74-8E26C5D499AF/live.4.indexHead
mds_store   354                   root  256r      REG               1,37   29900397             3169322 /Volumes/Time Machine/.Spotlight-V100/Store-V2/F2A3B1DA-3027-4BE7-BD74-8E26C5D499AF/live.3.indexPostings
mds_store   354                   root  259r      REG               1,37   35188048             3066720 /Volumes/Time Machine/.Spotlight-V100/Store-V2/F2A3B1DA-3027-4BE7-BD74-8E26C5D499AF/live.2.indexPostings
mds_store   354                   root  283r      REG               1,37  284414994             3066431 /Volumes/Time Machine/.Spotlight-V100/Store-V2/F2A3B1DA-3027-4BE7-BD74-8E26C5D499AF/live.0.indexPostings
mds_store   354                   root  284r      REG               1,37          4                 102 /Volumes/Time Machine/.Spotlight-V100/Store-V2/F2A3B1DA-3027-4BE7-BD74-8E26C5D499AF/0.indexPostings
mds_store   354                   root  289r      REG               1,37   68827035             3066616 /Volumes/Time Machine/.Spotlight-V100/Store-V2/F2A3B1DA-3027-4BE7-BD74-8E26C5D499AF/live.1.indexPostings
  • 1
    Do you have multiple partitions on it for different purposes? mds is 'Spotlight' not Time Machine, so I presume it's indexing something on there.
    – Tetsujin
    Commented Mar 14, 2022 at 18:07
  • Nope no other partitions.
    – Max
    Commented Mar 14, 2022 at 18:32

2 Answers 2


Spotlight and mds is how the backups work. It runs basically whenever you have file access by design so looking for it will cause it to run. Your open files are needed in case you decide to search for something, so ejecting the drive will free up these resources for other tasks / recording work.

I wouldn’t worry about this at all unless there’s a different measurable issue you want to focus on. I eject the drive when I don’t want it running and that will cut off all your issues and then you don’t need to manage the schedule as much.

  • 1
    But why is it running when I'm not accessing Time machine or backing up to Time machine? The issue is the sound of my drive spinning up constantly. I would think I could make it so the drive is only accessed at night during backup (or if I specifically access the Time Machine backup to recover something)..
    – Max
    Commented Mar 14, 2022 at 18:33
  • Sounds like you’ll want to use fs_usage to track what specifically is being accessed there… once you mount your drive and disable backups, does the activity die off after 15 minutes? Apple triggers the check for backups hourly whether you have TM paused, but the IO should be brief in that case
    – bmike
    Commented Mar 14, 2022 at 18:36
  • This does sound similar to a Mac I have which serves, amongst other things, as a TM backup for other Macs. They're all set to only backup overnight using TMEditor, but the Mac wakes maybe once an hour anyway to do… something.
    – Tetsujin
    Commented Mar 14, 2022 at 18:37
  • @Max the open files are index files. Spotlight needs them open to search and you can’t opt out of it. Ejecting the drive before your session solves all issues I can see for you.
    – bmike
    Commented Aug 11, 2022 at 20:29
  • 1
    Thanks! Wrote a script to mount/unmount daily. Solved everything!
    – Max
    Commented Aug 12, 2022 at 21:40

I can't replicate your exact setup here, but I would suggest doing the following:

  1. Open System Preferences

  2. Click Spotlight

  3. Select the Privacy tab

  4. Click + and add your Time Machine drive (the whole drive) to the list

Hopefully this will stop mds from accessing your Time Machine drive for indexing. Let us know if it works!

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