Stop Big Sur from writing Spotlight and other files to external MSDOS format volumes (SD cards)

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Stop Big Sur from writing Spotlight and other files to external MSDOS format volumes (SD cards)

I have an M1 MacBook Pro running Big Sur 11.4 and I have occasion to worm with MSDOS formatted external media (typically SD cards). Big Sur keeps writing various Spotlight and other files to my SD card even though I have tried to add my external volume to the "Privacy" table in Sys Prefs even after I use Disk Utility to format the SD card. Is there any way to prevent Big Sur from writing files to the SD card that I don't tell it to write? This causes havoc with some embedded devices that get confused if they see these "foreign" files.

Here is an example of all the junk that Big Sur writes to my MSDOS (FAT16) formatted SD card, none of which are useful to me:

/Volumes/ECOWITT> sudo ls -laR
Password:
total 60
drwxrwxrwx@ 1 _unknown  _unknown  16384 Jun 30 13:57 .
drwxr-xr-x  5 root      wheel       160 Jun 30 13:56 ..
drwxrwxrwx@ 1 _unknown  _unknown   2048 Jun 30 13:56 .Spotlight-V100
drwxrwxrwx@ 1 _unknown  _unknown   2048 Jun 30 13:42 .Trashes
-rwxrwxrwx  1 _unknown  _unknown   4096 Jun 30 13:57 ._.Spotlight-V100
-rwxrwxrwx  1 _unknown  _unknown   4096 Jun 30 13:57 ._.Trashes
drwxrwxrwx  1 _unknown  _unknown   2048 Jun 30 13:56 .fseventsd

./.Spotlight-V100:
ls: .Spotlight-V100: Operation not permitted

./.Trashes:
ls: .Trashes: Operation not permitted

./.fseventsd:
total 40
drwxrwxrwx  1 _unknown  _unknown   2048 Jun 30 13:56 .
drwxrwxrwx@ 1 _unknown  _unknown  16384 Jun 30 13:57 ..
-rwxrwxrwx  1 _unknown  _unknown     36 Jun 30 13:56 fseventsd-uuid

Note also the ridiculous system protection that prevents me, as root, from even looking at, let alone deleting, these files.

Does Big Sur have an "I am not a noob and need to have my hand held" mode flag that I can set?

Of note is that Windows 10 does not write random files to external media.

Thanks for any help.

Posted on Jun 30, 2021 2:03 PM

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Answer 1

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Barney-15E

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116,782 points

Jul 6, 2021 5:44 PM in response to Mike Bender

Is there no global flag to tell Big Sur to not write any system files to volumes using some sort of rule?

There is this, but I’m not sure if it works for externals, or goes far enough, hence the success of BlueHarvest.

https://support.apple.com/en-us/HT208209

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Answer 2

Mike Bender Author

Level 1

36 points

Jul 6, 2021 10:34 AM in response to Mike Bender

Update: I plugged in my Garmin chartplotter (marine GPS) which shows up as a USB mass storage device and Big Sur dutifully wrote the OS-specific files to it. This really doesn't make any sense in any practical way.

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Answer 3

Mike Bender Author

Level 1

36 points

Jul 6, 2021 12:14 PM in response to a brody

a brody wrote:

You can drag any storage device into Apple menu -> System Preferences -> Spotlight -> privacy if you don't want it to index the device.

Thanks, I tried that but what I found is that it doesn't remember this if I remove the device and then reinsert it.

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Answer 4

Mike Bender Author

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36 points

Jul 6, 2021 12:17 PM in response to Matti Haveri

Matti Haveri wrote:

I have made an Automator applet that cleans Mac-specific metadata files from non-Mac flash drives.

Or use BlueHarvest.

http://www.zeroonetwenty.com/blueharvest/

Thanks those are good suggestions but they remove the files after they have been written to the disk. I am looking for a solution that prevents the OS from writing those files to the disk in the first place. And - for BlueHarvest - I shouldn't have to pay money to buy a utility that prevents the OS from doing something that it shouldn't do in the first place.

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Answer 5

Barney-15E

Level 10

116,782 points

Jul 6, 2021 1:17 PM in response to Mike Bender

It actually needs the spotlight directories on the external to remember to exclude it. The list of exclusions is not stored somewhere on the Mac. it is stored in the spotlight directories on the drive you are excluding.

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Answer 6

Mike Bender Author

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36 points

Jul 6, 2021 1:49 PM in response to Barney-15E

Barney-15E wrote:

It actually needs the spotlight directories on the external to remember to exclude it. The list of exclusions is not stored somewhere on the Mac. it is stored in the spotlight directories on the drive you are excluding.

That's good to know and that design makes sense from the point of view of wanting to be able to have directory-level granularity for exclusion (can you imagine the size of the database that would accumulate if the Mac itself kept track of every excluded directory on every device it had ever seen!).

Is there no global flag to tell Big Sur to not write any system files to volumes using some sort of rule?

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Answer 7

Jul 6, 2021 11:55 AM in response to Mike Bender

I have made an Automator applet that cleans Mac-specific metadata files from non-Mac flash drives.

Or use BlueHarvest.

http://www.zeroonetwenty.com/blueharvest/

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Answer 8

a brody

Level 10

84,061 points

Jul 6, 2021 12:00 PM in response to Mike Bender

You can drag any storage device into Apple menu -> System Preferences -> Spotlight -> privacy if you don't want it to index the device.

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Stop Big Sur from writing Spotlight and other files to external MSDOS format volumes (SD cards)

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