Suddenly, I can only read all of my back up disks, and there seems to be no way to get "write" permissions. In the Disks Info screen, under Sharing and Permissions, only "you can only read" appears. There is no option for permission to Write.
MacBook Pro 13″, macOS 10.12
Is this an Intel or M1 Mac? Have you ever used these drives with this Mac before having the "read only" issue? Some third party devices are not compatible with an M1 Mac. Also, macOS 12.x Monterey is known to have some compatibility issues with certain devices from time to time depending what Apple has done with each minor update.
Also, it seems you posted this within the High Sierra forums, but are dealing with a 2020 laptop. I'm assuming you have an older laptop as well which is where these drives were used? If so, do you have the problem with the older system?
FYI, macOS 12.x Monterey now uses an APFS volume for TM backups which may explain why you cannot write to the drive. Did you have this issue before with an older version of Monterey, or did the issue only begin after the 12.6 update (or even an earlier 12.x update)?
I definitely would use DriveDx to check the health of the external drive as @BDAqua suggested especially if the drive was being used on your older Mac for years before using it with the new one (assuming you are going to erase it for use with the 2020 laptop and don't care about the historical backup). No sense putting important backups on a drive if it may be failing.
One big reason tis ha[[ens is the OS thinking Disk failure imminent...
Start with this...
Safe Boot, (holding Shift key down at startup), does the problem occur in Safe Mode? Could take 10 minutes or more.
Safe mode attempts to repair Disks & clears lots of caches & loads safe Drivers, & prevents loading of 3rd party extensions, so if Safe Mode works try again in regular boot.
You can use Drive DX to possibly get a better view of Drive health…
Simply put, It appears that Time Machine on hard drives created on the previous OS is not recognizable by OS 12.6.
Thanks. I did that twice. It took no time to start-up. Also, I used Disk utility First Aid. But I can still only read a portable HD; there is no permission option to write. I have MacBook Pro 2020, Mac OS12.6 . I have several backup HDs for time Machine, and have had no problems for many years.
OS12 does require APFS format for TM drives, I wonder if that is it?
That is likely answer, but could Apple have been so ignorant by making all prior Time Machine backup useless (WITHOUT A SOLUTION, NAD WITHOUT NOTICE)?
Agreed.
No "Write" permission option for hard disks
