SD and Time Machine
 

I have two Time Machine disks connected at all times, they run alternating Time Machine backups. I also periodically connect a clone for SuperDuper and run it.

This is for a MacBook Pro that is on Catalina. After the recent move from Mojave to Catalina, now sometimes I get an error message for a Time Machine backup that failed, but I ONLY see this when I am doing a SuperDuper backup (incremental), never at other times:

Time Machine couldn't complete the backup to xxxx Two of the disks to back up have the same name. Rename one of the disks named “Macintosh HD”.

Is this somehow related to the "clone" of the disk by SuperDuper? I have been dismounting both Time Machine drives during SuperDuper to avoid this. But it seems that something may be wrong with my configuration?

This is a weird bug in Time Machine when it sees that we've mounted Recovery at the same time it wants to. Rather than waiting for the volume to unmount, it throws an error.

Thanks for your quick reply. I figured you knew what was going on. It's not a harmful error because a later Time Machine seems to work. I'll just continue using both Time Machine and SuperDuper and dismounting the Time Machine disks temporarily for SuperDuper. I want to have at least two independent/different types of backup.

It seems that simple things used to be easier before Catalina and Big Sur. Now it's getting more complex. Although I like the stability of Catalina (I have a new Macbook Pro which is about one year old and it has never experienced a kernel panic or a freeze, at least not yet, it is still on Catalina).