External Hard Drive Missing After Big Sur Download

Love that when you go to reply, the dialogue box opens with "Tell us what's on your mind."

What's on my mind is it is pretty obvious this is a widespread problem that only began with the release of Big Sur. This thread goes back to the release of it. It's not something that just arose over the last two weeks.

It's spread across a wide variety of machines and many, many different HDs of all different capacities made by many different manufacturers. It so clearly is a Big Sur caused problem. I just don't understand why Apple's MacOS group is non-responsive.

The number of people expressing they have the problem just keeps getting bigger and bigger.

Come on Apple. Help us. Let us know you are listening.

This thread originally started with drives failing to mount and various work arounds. As it progressed, some people posted Big Sur was responsible for their content being erased from their drives.

While they have Big Sur in common they are two separate issues and I wish they had not been blended into this one thread. While I have compassion for anyone who data was erased, I do not believe they are linked and have to think if they got erased something specific, but unintentional was done by users that caused this.

While the failure to mount issue has been widespread and posted and discussed on many different Mac sites, spontaneous erasure has not and I am not able to turn up much about it floating around the web. To me, it confirms these are not linked problems.

Apple's non responsiveness to the mounting issue is what is frustrating. No acknowledgment of any kind despite multiple threads on apple discussion boards. We know they listen and watch these boards. How about it Apple?

I work on a variety of machines ranging from Windows PC to Apple Built Mac\win to Hackintosh. I recently restored a MacBook Air 2013 that a child uses for schoolwork, and updated it to Catalina. Everything was fine until the kid updated to Big Sur.

I used a third party, "Compatible" disk, that wasn't "completely" compatible, but only found out at the time of the restore. The problem at the time was that the disk was PROVIDED by my clients, not by apple. Every other manufacturer uses a WIDE STANDARD for compatibility. Apple made the mistake of NARROWING from their stated compatibility; the reason for it is unimportant, they flat out lied to the entire world, not a small community. Not a happy event. They did, eventually revert to a wider standard with a later firmware\SMC combination. This allowed me to use an old, used disk (I purchased from a friend who had wiped his old MBA disk after the MBA suffered a main board failure) to update the machine, and transfer to the new disk, though it took a serious reworking of the whole process. I had to use the old, low space hardware to install to the new hardware, Via a restore process. It worked.

1. Install Mac OS onto one internal disk
2. Run the installer to install to a second disk\partition
3. Run disk utility to restore from the second disk to the third party disk, along with the EFI partition etc
4. Set the machine to boot from the new, third party disk

It worked for more than 6 months on Catalina. Updating to Big Sur killed it. Now at boot up, I can see the disk when I press alt. However, I cannot get it to boot. I cannot get the internet recovery environment to read the disks either. It won't show the usb external no matter what I do. They work fine on other machines, even in windows with special APFS\HFS drivers. They are seen by "SYSTEM REPORT" in Mac OS, but they are not loaded in disk utility or in the finder. All Darwin command line commands don't see them either.

I've tried many old MBA disks (apple branded) and they do not show up unless internal to the machine.

Big Sur has KILLED USB or rewritten it's protocol somehow, making it impossible for older machines to utilize.

ttppee -

I believe the NTFS issue and a solve has been addressed in this thread, which I just checked and see is now 13 :( pages long. Apple is not listening. The thread starts out back in Nov. as a decent and hopeful (trusting actually) question to Apple support. Now months later it is a stream of reported issues, disappointment and anger. Because: Apple DOES NOT CARE!! Surprised they haven't purged this thread. Go back and read through.

well I solved my drive issues with Catalina by restoring the original system that came with my computer, then worked my way back to Big Sur., this took 30-40 PRAM restarts just to get the restore to kick in.

The last BigSur update just ruined this and I should mention that its very hard to restore when your drives vanish internally and externally., especially internally, cause when they do the wifi won't work as normal which means you can't restore, you can't even from a usb stick., you have to reset the PRAM with a battery disconnected.

Epiphany-uc wrote:

Helpfull button won't function in this thread? Why not? Thanks for your post. Sounds incredibly beyond my abilities. BTW just found my old Time Machine. It will not mount. Never even asked to enter a product key. Beyond awful.

https://discussions.apple.com/content/attachment/6a85805b-82ea-4ad1-9c16-8f4d13976f41

Ne

says NTFS, (New Technology File System) is a proprietary journaling file system developed by Microsoft. 

Big Sur is compatible https://www.m3datarecovery.com/ntfs-mac/ntfs-for-mac-big-sur.html but clearly somethings wrong.

Hey there!

This is a long thread, so I haven’t read it all.

However, I’ve found that ANY time, I start to use an external hard drive with a Mac, I make SURE it’s formatted in a way that will always be able to read/write to/from. Although I definitely know software and hardware fails at times, which, to me I expect, despite which brand of computer you have, so routinely keep a few backups, as external hard drives can hole a lot of storage while remaining fairly affordable.

Formatting your external hard drive from the get go should, (but isn’t guaranteed to), keep your data safe. Which is why if I start backing up a new Mac, I check the formatting, storage, etc.

In each case, I start the formatting in Disk Utility, on the new OS’ make sure to select on the top menu: View > Show All Devices. Then select the TOP level of your external hard drive, then select the Erase tab:

When I plan to user a drive solely for Mac, I format as so:

Name:

—Give it a name.

Format:

—Mac OS Extended (Journaled), or APFS if necessary.

Partition Map:

—GUID.

If I plan on using the external hard drive for both Mac AND Windows OS’, erase the same way using:

Name:

—Give it a name.

Format:

—ExFAT.

Partition Map:

—Master Boot Record.

This should assure you that you won’t have problems reading from/writing to, these drives. Although formats change every now and then. And likewise external hard drives do fail or get corrupted and need to be erased. (As internal). Which is why it’s best practice to have a backup of a backup.

Hard drives do have a life span, so unfortunately they are not the fountain of life. However are readily available for decent prices, and do come in handy. Likewise cloud services are another option, (iCloud, Dropbox, One Drive, etc. etc.). However, even data stored in a cloud service should be backed up elsewhere, as servers do fail, no matter the company. Likewise, data gets corrupted, for a number of reasons, e.g. the account is constantly attempting to upload, or a device is attempting to download more data that it can handle or has room for. (One example).

Hope this helps someone, otherwise, best of luck, everyone here is here to help.

thill7 wrote:

Hi Old Toad, thanks for your help!

Format seems to be "Mac OS Extended", here a screen capture:

That drive is being used by Time Machined and should not be used for general storage.

If you need additional general storage then get another external HD and use it. It can also be backed up to TM drive with Time Machine.

Hey Xenocide38!

Well done! I think, however, when running a disk repair, “First Aid”, it’s best to do it while booting to the recovery partition. This way, you are not booted from the internal, or external drives. I’ve seen repairs/erases/etc. fail when run while logged in, yet work fine while in recovery mode. (Single user mode was discontinued years ago, unless you still have an older Mac with an older OS, but you can boot to recovery mode now if you need to):

https://support.apple.com/guide/mac-help/about-macos-recovery-mchl46d531d6/mac

Otherwise, hope your trick fixed it! That’s good to know!

If you have to get another external HD seriously consider one from OWC (MacSales.com):

Envoy Pro EX with USB-C or USB 3 - best from a speed vs price standpoint

OWC Envoy Pro EX with Thunderbolt 3 - fastest if you have a Thunderbolt 3 port but more expensive

 OWC Mercury Elite Pro 7200 RPM Storage  - excellent choice for Time Machine use.

Hey Rockingdee, I am facing a similar problem and was just checking in to see if you have found the solution.

I have a 5TB Seagate Portable Backup Plus which was running fine till I updated my Air to Big Sur. It was ExFat formatted. It shows up on Windows and even my older Mac.

I took a backup of the disk and reformatted it. But no luck. I even formatted it to APFS, but it's still not showing up. Even in Disk Utility.

Funny thing is that my WD 1TB external hard drive works. So I don't know whose fault it is, Seagate's or Apple's.

If you have a solution please let me know. (I have tried downloading Microsoft NTFS, Tuxera too. No Luck)

Thanks!

Apple support personal are not here. We're all users like yourself. If you want to contact Apple directly and tell them about your problem use this link: Feedback - Photos - Apple

How is the drive formatted?

Can you see it with Disk Utility?

I have ALSO been having Drive and disk issues. This new bigSur MacOS is not as great as previous builds. Some things are nice and cool about it, others are absolutely terrible, like the finder window and toolbar space.... But back to the drives.... Mac OS Big Sur will trip on my external ExFat drives most notably after they are mounted on my windows 10 pc. I could also tie the issue to windows except that my older macbook running high sierra does not present those issues. Can you guys Downgrade/upgrade diskutil, and disk utility to that of older versions of Mac OS when First Aid actually fixed something, or gave us more controls to fix drives, permissions and etc?

I'm not sure if there is a way to 'fix' this without reformatting. I've been trying to format any disks I get to APFS since Catalina.

Also thanks for the detailed response.

I had to use Terminal's diskutil to fix this... s

Seems Apple's GUI Disk Utility has become pretty flaky in the newer OS's and no longer displays the partition table schemes. :-(