Level 1

41 points

SD Cards formatted in FAT32 mount in macOS 15 (Sequoia) as "NO NAME"

Anyone else noticing this since moving to macOS Sequoia?

Recently installed Sequoia 15.6.x from macOS Sonoma.

SD Cards that have a Volume Label under the 8 character limit, formatted in FAT32 always mount as "NO NAME".

However when the same SD Card is formatted as ExFAT - it mounts intact with volume label also correct.

I have tried formatting with official "SD Card Formatter" (both "Quick" and "Overwrite" formatting), formatting in Disk Utility and Terminal. All SD Cards are SanDisk 32GB Extreme Pro (300Mb/s) - but it presents the same issue when formatting a standard USB flash drive, so surely it's a bug with the diskutil backend?

Disk Utility reports no issues with the card, and no directory damage.

Running maOS 15.6.1, iMac 27-inch (intel), 64GB RAM.

Posted on Sep 9, 2025 12:07 AM

Top-ranking reply

HWTech

Level 9

68,618 points

Posted on Sep 10, 2025 6:51 AM

When using Disk Utility to erase a drive, make sure to select the physical drive which unfortunately is hidden by default in Disk Utility. Within Disk Utility you may need to click "View" and select "Show All Devices" so the physical drives appear on the left pane of Disk Utility. This is the only way Disk Utility may alter the partition table....erasing just the existing volume is unlikely to modify the partition table.

If that does not make a difference, then I would suggest writing zeroes to the entire SD Card (beginning of SD Card is probably enough), but this requires using the command line where it is easy to make a catastrophic mistake if you have any other external drives connected. I can provide instructions if you wish to try this option. Sometimes things may be hidden in areas (usually at the beginning of the drive) which may not be touched when creating a new partition table with some utilities.

View in context

24 replies

oz-macnut Author

Level 1

41 points

Sep 10, 2025 10:22 PM in response to HWTech

Thanks HWTech. All valid points and I always format the drive using the physical designation rather than the logical volume. (I.e - disk4 rather than disk4s1)

I don’t use disk utility normally to format flash media (especially these SD cards) as Presonus recommends using SD Card Formatter to throughly overwrite the entire volume (same as your suggestion in Disk Utility).

The volume name issue has not been prevalent until I migrated to macOS 15.6.1 Sequoia. I format these cards every week - the only change is macOS update. The cards only failed to write data if I used Disk Utility, so I stuck with the recommended and stable app.

steve626

Level 6

13,791 points

Sep 13, 2025 11:06 AM in response to oz-macnut

I am sorry, I tried with FAT32 and FAT16 on some jump drives but cannot reproduce this issue. When I rename the drives on a Sequoia Mac they stay with the new name after ejecting and remounting. I am wondering if there is something in your setup or maybe the way you are formatting your drives that is causing this?

oz-macnut Author

Level 1

41 points

Sep 14, 2025 3:00 PM in response to Matti Haveri

Safe Boot is something I do frequently, but I prefer the more comfortable option of using Onyx to clear caches and other deeper options (like local snapshots, fonts and print caches, indexes etc). I’ll give safe boot a shot. Thanks.

oz-macnut Author

Level 1

41 points

Sep 9, 2025 3:06 PM in response to tbirdvet

Does it stay when you eject the card and remount it? Do you have the card format as FAT32 or ExFAT?

Sep 10, 2025 10:34 PM in response to oz-macnut

Look in the boot parameter block (BPB):

https://academy.cba.mit.edu/classes/networking_communications/SD/FAT.pdf

See if it’s what you expect.

Appendix 2 is an example.

oz-macnut Author

Level 1

41 points

Sep 11, 2025 1:07 AM in response to MrHoffman

Thanks for that resource MrHoffman. How is it best to check the BPB on the volume with specific tools? Is there a Terminal command that will show that byte blocks?

Can someone reproduce my issue?

tbirdvet

Level 6

17,078 points

Sep 13, 2025 7:42 AM in response to damian_2287

No issue for me. After renaming the name does not change when I remount the disk.

oz-macnut Author

Level 1

41 points

Sep 14, 2025 3:02 PM in response to markwmsn

I will add that to the collection of options to test! Thanks markwmsn

oz-macnut Author

Level 1

41 points

Sep 14, 2025 3:58 PM in response to oz-macnut

Safe Boot - no change. Volume name will show up if mounted during boot. Eject volume and remount - NO NAME"

This thread has been closed by the system or the community team. You may vote for any posts you find helpful, or search the Community for additional answers.

SD Cards formatted in FAT32 mount in macOS 15 (Sequoia) as "NO NAME"