External Hard Drive Missing After Big Sur Download

I am having the same issue with my 5TB WD Easystore HDD. Stoped doing back-ups and then I noticed it will not mount. I tried the power thing, mounting from terminal, etc...I can not even erase it to start from new. What the heck is going on? I remember when Apple products just worked. Please help

I feel for you. These problems seem weirdly random? There are other suggestions in this thread, so read back. The last BigSur upgrade solved my problem with an external CD reader, however I have not yet checked my HD backup. I am still considering removing Big Sur and going back to Catalina.

Thanks for the response. I have tried everything. I can't even erase it. I dowloaded the latest software from WD, changed cables, etc....My Samsung external works fine on the same computer?? Makes no sense to me.

So sorry. Have you called Apple tech support? Do they still work since Covid? Have you thought of uninstalling BigSur? What are the advantages of BigSur that justify the time/cost/benefit? I'd better find my HD.

I had a similar problem. Though the upgrade to Big Sur failed so did my two external hard drives. Apple says that it is not thri fault and that I have to go privately to a Data Recovery Company which is very expensive.

Hmm my 1TB drive mysteriously died too. Tough it is 11 years old i still think there was life in it. I amable to plug it into a mac with high sierra and slowly get data off it before it bombs out completely. I have a second 500G drive that connects fine.

Time to go to the cloud with my photos.

So sorry for this major and inconvenient hassle. Are your HD failing to mount or did they get erased? Were they plugged in when you loaded the upgrade? How did they get erased? Hearing this is about the last straw for me. What is wrong with Apple? the known issues with BigSur are noted daily, a different one every other week. I think I will definitely go back to Catalina.

Perhaps you could be more specific about what you mean when you say they failed. I have trouble understanding how Big Sur could cause a failure that only data recovery services could fix. Was there a mechanical failure? Are they HDD or SSD drives?

I wonder if Samsung's disk software would resolve it for me? I am hesitant since all my backups are on that T5 drive. I would be very unhappy if something happened to my data while installing the software.

I still have not been able to retrieve my data. I tried several retrieval software and they are not showing anything, so I fear that all my data are lost. I think they were probably plugged when I did the upgrade though I don't remember as the upgrade was taking a very long time. The message I get when I try to mount my external drives is "The disk you inserted was not readable by this computer" with the options to initialise, ignore or eject. I don't think it is a conicdense.

They cannot be read by any computer. Went to Genius and they could not solve the problem. They suggested I go to a private data retrieval company which is very expensive.I also don't know how they failed but since I saw that others have experienced related problems with Big Sur there must be a connection. I also went to other forums online and they are also reporting similar issues.

Disappointing and infuriating. the discussions around the web re: BigSur Failures are numerous.

People report having called and gotten nowhere. They should take responsibility.

I am uninstalling it and going back as soon as I have time.

hey..

Tried the exact thing today. bought a 2020 MBP Saturday, migrated everything to my new mac, and yesterday thought it would be a good plan to backup my new mac with my WD ext HD. No such luck.....couldn't mount, doesnt show up in finder and cannot erase. Called apple and had no luck, took to the Genius bar today and the tech said" my ext. drive is bad"! I left there in disbelief.....its hardly even been used, I think he may not have been a "genius"!

I am having the same exact issue and i have five different hard drives (mostly full of music i created in Ableton/logic etc) that all worked perfectly before the Big Sur update. I also can't use certain software for my Roland gr-55 guitar pedal now. My brand of hard drives are three of them being seagate and the other two are wd my passport. This is extremely frustration because most of these are filled with music I created that cant be replaced as well as old photos and projects from school and work. Please help there is no way that I am deleting these or resetting them. I have a MacBook pro-2017 so it is not that old of a laptop.

hilarypost What size is your MacBook Pro (13", 15" or 16")? What year is your MacBook Pro? How much RAM and storage is currently installed on your MacBook Pro? What brand and model of external hard drive are you currently using?