upgraded from catalina to bigsur (finally) photos wont open migration failed and repair is failing

i had a 3 months old TM backup but that was irrelevant because it was the upgrade process that was failing, first the migration failed then the repair failed repeatedly. Even if I had restored a 1 day old backup of the library I would have had the same problem. The issue is the upgrade to bigsur needed the photo library migrated. The migration process is too weak. Thus the issue is MacOSx and google interoperability, and MacOSX not explaining the upgrade process adequately, ie if using photos when you move to Big Sur your photos library will have to be migrated. Thankfully I have everything backed up with google photos so any apple issue doesn't impact the overall integrity of my photos. Its just that ive put a ton of time into organizing the app Photos and didnt want that lost if i could help it.

i have a 3 month old backup and no it wasnt syncing with icloud as i didnt have the storage space on there, but ironically just upgraded it and was about to. I do have a back onto google cloud but not in the same format i had photos all set up for with events etc . So if i have to dump it all not overly impressed just because of apples useless upgrade service , ill switch it all to google and put it down as another bad apple experience. Below is the activity mon relevan photos events i cant if its doing anything or just stopped. My guess is the migration is failing because of 1 particular file , either type or size that apple have not catered for . Do you know if there is a way of resetting the album removeing the plist or something and just rebuilding it. ? I guess i will lose all my events and config though

Hi there thanks for the reply. the photos library is the in the photos folder on the boot drive in the mac, itsthe exact same file name as default never changed. It was working fine with catalina, then i upgraded to big sur and first time i tried to open photos it said migrating photo library and failed. Now its still trying to repair and after 24 hours its at 3% as i write. Like i said it did do 1 cycle and got to 99% quickly then started this cycle and stuck at 3% and still stuck 2 days later. I can see all the files in the package (show package contents) in the library Ive got still and video all of which worked before. So is there any way of rebuilding the library from the package itself or do i have to try and fix the indexing the photos app uses. ? Ive got 370GB of 2TB available on the drive that the photos file is on ...

I'm still stuck stupid apple software 1tn$ company and my experience of their OS is next to useless. the library still doesn't get past 4% so my guess is it's failing to index a big file event or folder but don't know how ill ever find which one. I've got all the photos on google thankfully as simply cant trust the apple apps , photos is failing here for me and i should have reduced the size of my library into multiple libraries but you would think apple would know this and creat the app so it would suggest a solution as you use it and as the library expands. hey ho live and learn dont trust apple apps , thanks to all those who suggested solutions

Well fixed !! thought id post an update, so I watched the repairing of the library and tried multiple times and always failed at 4%. On one occasion i saw google drive failed to backup a photo at the same time as the repair library failed. So I paused the synch google drive (v55.0.3.0 intel) . I then attempted to repair the photos library again and 12 hours later voila my photos library is now back and working and thankfully all intact. What a miracle !! so some problem with google drive opening photos.db whilst the repair process was operating, you would think the repair process would lock the library not the other way round. Anyway, it now is working and I intend to reduce the size of the library files into smaller workable libraries. thanks again to all those who looked and suggested

like i said the backup whether 1 day of or 1 months old would have made no difference. As far as i can tell after a month of trying to resolve it the problem has been resolved exactly as i have stated. Paused Google drive , Ran photo repair and voila , the first time photo repair worked in 30 attempts. There's nothing complicated about my setup. If the upgrade said migrate your photos after the upgrade , be aware that anything that may have access to the photos database like google drive, dropbox mcafee whatever may interfere with the migration - then I would have tried that earlier. Thus imo migration should lock access to the files during migration or repair to avoid this problem.