Time machine not working

paridown wrote:

I'm running Catalina 10.15.7 and Time machine was working fine, the external disc has plenty of capacity, but now the backup stalls around 25% through. Have "skipped" and tried again, no go. When I try "verify"using the option key "verify" is shaded so I can't select it.

"Time Machine has completed a new backup for you, or get a message saying it can't create the backup,"

or “failed to complete the backup, ” or “Preparing backup”

This message reappears most likely the TimeMachine disk is operating in a state of failure and will continue to fail with increasing frequency, in this case replace the drive.

Trouble Shooting Time Machine

https://support.apple.com/guide/mac-help/time-machine-troubleshooting-mh15653/mac

Now the Time Machine Preferences won't open. I rebooted the machine which did not help. I unmounted one of my TM drives and am going to let the current backup run and hope for the best, The current backup has been running for 4 hours and says 29.5% done 11.6GB copied. I certainly haven't added more than a few MB in the past few days!

I recently started doing that. I unplug the drive I’m not using so it would not even be powered. Remove it from Time Machine and unmount it before doing that. One on my drives just died. 😩

It's been in the Stopping state for about 3 hours.

If the disk is going bad, why can MacOS notify the user that the disk may be failing, and suggest some plan of action to save what is on the disk? My general sense of using Time Machine for many years is that Time Machine backups your files until the disk fails and you've lost all that you've saved. I always run two time machine disks because this has happened to me SO often.

…why can’t MacOS…