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

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oz-macnut Author

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

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Answer 1

oz-macnut Author

Level 1

41 points

Sep 11, 2025 04:17 AM in response to MrHoffman

MrHoffman.

You have certainly enabled a bit more information to be gleaned. Thanks for the µSoft FAT Specification.

This is indeed a macOS 15.6.1 Sequoia bug! As I have repeatedly mentioned: This issue did not present itself on my machine under Sonoma.

Checking the BPB as per the Appendix 2 - as you suggest.

Interrogating a formatted FAT32 SD card - one that should have a Volume Name "PRESON2" - but is shown in the Finder as "NO NAME".

Using the following commands in Terminal, on the unmounted SD Card:

sudo dd if=/dev/disk4s1 of=bootsector.bin bs=512 count=1
xxd bootsector.bin

The resulting BPB hexdump is:

1+0 records in
1+0 records out
512 bytes transferred in 0.000746 secs (686327 bytes/sec)
00000000: eb00 904d 5357 494e 342e 3100 0240 3404  ...MSWIN4.1..@4.
00000010: 0200 0000 00f8 0000 3f00 ff00 0020 0000  ........?.... ..
00000020: 00e0 bc03 e61d 0000 0000 0000 0200 0000  ................
00000030: 0100 0600 0000 0000 0000 0000 0000 0000  ................
00000040: 8000 29dc 8f1a 8b50 5245 534f 4e32 2020  ..)....PRESON2  
00000050: 2020 4641 5433 3220 2020 f4f4 f4f4 f4f4    FAT32   ......
00000060: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
00000070: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
00000080: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
00000090: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
000000a0: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
000000b0: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
000000c0: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
000000d0: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
000000e0: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
000000f0: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
00000100: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
00000110: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
00000120: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
00000130: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
00000140: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
00000150: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
00000160: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
00000170: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
00000180: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
00000190: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
000001a0: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
000001b0: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
000001c0: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
000001d0: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
000001e0: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4  ................
000001f0: f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 f4f4 55aa  ..............U.

I have discovered, in the human-readable column, row 040: we can see that the Volume Name "PRESON2" IS certainly there in the BPB, however: It is not shown in the Finder!

Surely, this is grounds to suggest that this is a bug with the Finder not correctly parsing the BPB and returning the correct Volume Name.

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Answer 2

Sep 13, 2025 05:00 AM in response to oz-macnut

Yes, this is happening to my FAT32 USB sticks too. Definitely an issue post-Sequoia. I rename them - eject - re-mount them, and they show up as "NO NAME" again. But even if they show as "NO NAME" on my Mac - I can mount them on my partner's PC, and the old names I gave them have been preserved.

The issue persists even when I reformat in Disk Utility. It shows up as "NO NAME" even if I've literally just given it a name during the re-formatting process. However - if I reformat as ExFAT or MacOS Extended, no problem - the name appears, and stays, even after ejecting and re-mounting. So it's specific to FAT32.

Either way, it's annoying and should be fixed.

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Answer 3

den.thed

Level 10

88,954 points

Sep 9, 2025 07:46 AM in response to oz-macnut

The question is, what are you using these SD card for..?

It is normal for SD cards that have been formatted for or in a camera, to show up as NO NAME.

If you change the format of an SD cards, then it will no longer work in a camera.

SD cards are ment to be used in a camera and then used to transfer the images to your computer.

They can be used for archive storage, but are to fragile for everyday use and sharing.

Flash Drives are better for everyday use if your sharing images with other people and computers.

External Hard Drives are better for everyday sharing, archiving and backing up image files.

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Answer 4

Sep 9, 2025 03:30 PM in response to oz-macnut

oz-macnut wrote:

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.

If you can not rename it, then stick with ExFAT if it is an issue for you.

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Answer 5

oz-macnut Author

Level 1

41 points

Sep 9, 2025 04:36 PM in response to oz-macnut

I'll add details to answer further questions:

I have two SanDisk SD Extreme Pro 32GB cards that are used in rotation in a Presonus StudioLive Audio Console. Volume capacity maximum allowed is 32GB, and format must be FAT32 (as set by Presonus).

https://support.presonus.com/hc/en-us/articles/115000921126-Recommended-SDHC-Cards-for-Multi-track-Recording

The condition occurs with both the built-in SD card slot in the iMac 27-inch (2020, intel), and a USB3.0 multi-format card reader interface (Lexar), and across two separate iMac's (all running macOS 15.6.1).

The card is "overwrite formatted" (not a quick format) using SDCard.org's "SD Card Formatter" - every time it is used and has data copied from it, before being returned to begin copying again in the Audio Console.

I'd like people under macOS 15.6.x Sequoia to test for themselves to see if they can repeat this issue, and post back their findings.

** This is a destructive test for any data on the flash media - so consider carefully what you use to test.

1. Mount the volume and use Disk Utility/Terminal or your disk formatting tool, to format that drive as MS-DOS (FAT) - Master Boot Record. Make sure you give it a name under 8 characters long e.g. "SAMPLE"
2. When the newly formatted flash drive mounts in the finder, note what the volume name is... Is it what you named the volume when you formatted it("SAMPLE"), or has it returned to "NO NAME"?
3. In Finder, rename the volume - for laughs, rename it to something different under 8 characters long.
4. Eject that same volume, then remount it... Has your name-change stayed, or has it returned back to "NO NAME"?

Disk Utility, Terminal and the Finder all show the Volume Name as "NO NAME" - irregardless of how many times, you format it, or rename it - as soon as you remount the volume, the name is reset to "NO NAME".

I have tried this on SDHC, SDXC, SD cards of different brands (SanDisk, Kingston, Lexar) - all do not hold name when formatted as FAT32.

I get that people think this is a non-issue, but when you have multiple SD card ports, or multiple cards that you have to keep track of individually, then it's a problem for me. Plus, macOS "just works" - doesn't it? Or have we forgotten our legacy?

This behaviour was not observed before macOS 15.

I'd be interested to know if someone has macOS 14 Sonoma to do the same test above, and report back if the volume name is retained on mount.

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Answer 6

HWTech

Level 9

66,836 points

Sep 10, 2025 06:51 AM in response to oz-macnut

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.

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Answer 7

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.

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Answer 8

Sep 12, 2025 09:29 AM in response to oz-macnut

oz-macnut wrote:

Mount the volume and use Disk Utility/Terminal or your disk formatting tool, to format that drive as MS-DOS (FAT) - Master Boot Record. Make sure you give it a name under 8 characters long1. e.g. "SAMPLE"

2. When the newly formatted flash drive mounts in the finder, note what the volume name is... Is it what you named the volume when you formatted it("SAMPLE"), or has it returned to "NO NAME"?

3. In Finder, rename the volume - for laughs, rename it to something different under 8 characters long.

4. Eject that same volume, then remount it... Has your name-change stayed, or has it returned back to "NO NAME"?

I can't replicate this issue in Sequoia 15.6.1.

#2. Name "SAMPLE" is preserved when erasing a) the device as MS-DOS (FAT) - Master Boot Record and b) erasing the volume.

#3-4. Either way erased, and renaming in Finder as "SAMPOO" that new name is preserved even after eject and re-mount.

(Mac mini 2018, Transcend 32 GB SD card, USB-A card reader).

An EtreCheck report would eliminate much guesswork with your setup:

Using EtreCheck to Troubleshoot Potential… - Apple Community

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Answer 9

Sep 12, 2025 10:00 AM in response to Matti Haveri

FAT can have a second copy of the volume label in a directory (file) entry in one or both of the file allocation tables (FAT), with the attribute ATTR_VOLUME_ID set.

So there are three copies of this volume name data.

I’m not aware of any enforcement of consistency there.

I once wrote a FAT file system. It’s a bizarre design. Long file name support is a massive hack, too.

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Answer 10

steve626

Level 6

13,107 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?

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Answer 11

oz-macnut Author

Level 1

41 points

Sep 14, 2025 01:00 AM in response to damian_2287

Interesting damian_2287.

I have since done several shut down and restarts, and this time: I had sucess with the correct volume name being shown - BUT - I inserted the SD Card into the slot before a cold boot, and therefore the SD Card mounted before other volumes, e.g. /dev/disk2, not /dev/disk4.

I have tried a restart, leaving the SD card in the slot: The result is the Volume Name is displayed perfectly.

But, if you then unmount the SD card and re-mount (without restarting in-between) - boom: The "NO NAME" returns. The disk enumeration is therefore changing to a different number - it's fine on a reboot, but if that same volume is mounted a second time - without a restart in between - the volume name is not correct.

Is this condition something to do with diskutil volume enumeration? How many volumes do you have on your system? When do you insert the card for the issue to be OK/not-OK?

Try inserting the SD card, then doing a reboot, letting the SD card mount according to macOS naturally. Is the correct volume name shown in Finder? If it is, try ejecting and re-mounting the same card without a reboot. Does "NO NAME" come back on that volume?

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Answer 12

Sep 14, 2025 01:19 AM in response to oz-macnut

oz-macnut wrote:

I have since done several shut down and restarts, and this time

Does safe boot which clears some caches fix this? Maybe Finder incorrectly caches and displays such old name via some workflow? Oh, so many variables to test.

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