I get the above notice indicating Time Machine couldn't complete the backup because the backup disk is read-only. It was working just fine until I installed the latest OS (Monterey Version 12.5) The message says the disk is read only. It was backing up fine until installation new OS. Any ideas? What should I do?
I'm not a techie.
iMac 21.5″, macOS 10.15
Is the Time Machine backup disk a Time Capsule....or.... is it an external USB drive that connects directly to the Mac?
Did you update from another prior version of Monterey....or....did you update to Monterey directly from Big Sur or another earlier operating system like Catalina, Mojave, etc?
I updated from a prior version of Monterey. I do have an external USB connected to the Mac. But I think there's an internal backup too. The message has the picture of the Time Machine logo on it if that gives you any info.
Thanks, could you very briefly list any troubleshooting steps that you have already performed......so we don't ask you to do things that you have already done?
I don't have a Monterey Mac handy at the moment since I'm traveling, so it may be a day or so before I can see if I can duplicate the same issue.
Thank you so much. I appreciate your willingness to help. So far my troubleshooting has been to wait until it magically fixes itself, and ask the community. I am such a novice I don’t know where to start. I suppose I could try shutting down and restarting.
Yes, try the good old "turn it off" and then "turn if back on" trick as a basic step.
Shut down the Mac
Power off the external drive
Wait a minute
Power up the Mac and wait a minute
Power up the external drive
Try to run a backup
Click on the Time Machine "clock" icon at the top of the Mac's screen
Click Back Up Now
If an error occurs, please post back with the exact text of the message
Wow, now it says Time Machine couldn't complete the backup to "Untitled" The backup disk could not be found. Make sure the backup disk is connected or select a different backup disk.
I looked at the last backup is 31 July.
OK, thanks. Major malfunction. I will have my Monterey laptop tomorrow afternoon and will see if I can duplicate some of the issues.
Too early to know what the plan will be, but it is possible that the external will need to be erased and a new backup created. We'll cross that bridge when we come to it though.
Well, I've tried some things that you are not supposed to do in an attempt to try to create the same or similar issues that you are reporting, but so far no luck.
Will update on Monday.
Thinking ahead.........rather than a long thread of messages that are basically "try this" and "try that", you might consider getting on the phone with an Apple Product Specialist who can walk you through things step by step and answer any questions as they arise.
Issues like the one that you are experiencing are tough to deal with over an online support site with delays, etc in the process. There are no quick fixes, I am afraid.
Thank you so much for all of your help, Bob. I will call Apple just as soon as I have time to stay on the phone with them for awhile. In the meantime, and this may be a silly question, but please tell me if this could be the problem:
I notice that it says that "Untitled," which I assume is my backup disk, has 925 GB used. I'm pretty sure it is a 1 Terabyte disk. Is it possible that it doesn't have room for another backup? (tells me that full backup is 258GB) If it's full, wouldn't it just start deleting old files to copy new ones?
Anyhow, thank you so much again for spending your precious time on this. Glad you are back safely from your travels.
I notice that it says that "Untitled," which I assume is my backup disk, has 925 GB used.
I do not know why it says "Untitled" unless that is the name that you assigned to the drive.
Is it possible that it doesn't have room for another backup?
Yes. If the disk is 1 TB and you have used 925 GB, it is very close to full, and Time Machine requires a lot of free space in addition to the space for the backup to occur. But, if that is the issue, you will usually see a message to the effect that "There is not enough room for the backup to occur".
If it's full, wouldn't it just start deleting old files to copy new ones?
That's the theory, which does not work all that well in practice. IF.....a backup is a bit larger than a normal small incremental backup......which could occur after an update, new images have been added, etc.......Time Machine cannot delete enough old files to make room for the new backup.
I believe that after some discussion, that Apple Support will ask you to erase the backup drive and start over again with a new backup. Hope I am wrong.
Let us know how things turn out if you can. Good Luck!
Arrrrrgh! Thank you so much, Bob. I will be away most of the day tomorrow, but will check to when I get home to see what you suggest. Was so hoping it would just be something simple.
I wound up buying a new 4TB external backup, replaced the 1TB, and my iMac is back in business with no lost data so far. I’m happy.
Time Machine couldn't complete backup
