Daily Smart Update stalled after "Disk disk 8 vanished!"

[Ward]

The daily backup of my boot drive runs at 5:00 am. When I got to my Mac this morning, SuperDuper! was open, with the progress bar appearing to indicate the copy was nearly complete.

The log shows these lines at the end:

| 05:33:45 AM | Info | /dev
| 05:33:45 AM | Info | /net
| 05:33:45 AM | Info | /home
| 05:33:45 AM | Info | /Sandbox
| 08:35:06 AM | Info | Disk disk8 mount changed!
| 08:35:16 AM | Info | Disk disk8 mount changed!
| 08:35:16 AM | Info | Disk disk8 vanished!

"disk8" does not appear earlier in log.

What does this mean?

While I was researching this problem here in the forum, SuperDuper! apparently completed, with no Growl notification. Fortunately, I had captured a copy of the SD log in BBEdit while SuperDuper! was stalled.

-- Ward

[dnanian]

We're logging disk mount/unmount events during the backup, in case those events can shed light on failures that might occur during a backup operation.

Those mounts are likely Time Machine local (snapshot) or remote (network) volumes.

[keriah]

Is there anything further on this? I just got a similar message and the backup appeared to have stalled. I finally cancelled it. I'll attach a screenshot of the last few lines of the log. I am not using TimeMachine and there's no network drive involved here.

[dnanian]

If it's "stalled", it's likely going to get those logs if you have any other volumes being mounted: we're logging them all in case they're relevant.

Are you running CrashPlan?

[keriah]

"Are you running CrashPlan?"

No. (I don't recognize that name.)

[dnanian]

OK. Next time this happens, if it happens again, drop me a note to support *before* stopping it, so we can diagnose what's going on.

Was this on High Sierra (10.13.x) or an earlier version?