Backup seemingly hanging?

I have my duplicati set up to back up my files weekly, usually the backup process takes between 15 and 45 minutes depending on how many changes I have in the backup set…In 2 of the last 3 weeks it has taken 9 hours+, and I have no idea why - the UI just says “Running…” and if I try to view the log it says “Failed to connect: The database file is locked database is locked”. The first time this happened I rebooted the machine and started over, and it seemed to be happy…until this morning when I noticed it is doing the same thing again. I have not killed it yet this time…it is spinning the CPU so it seems like it is doing something maybe, but it’s taking way longer than normal, and again is not letting me view the logs.

my duplicati runs on a Linux machine, and accesses all the files via SMB shares…it has run great for a couple years like this, but then 3 weeks ago I changed the backend file store from being a windows machine to being a Linux machine (still mounted at the same path, so duplicati sees them as the same files)…the first backup after making the backend change took a day and a half, as it re-checked every file, and then after that it seemed to be happy…but now I’ve seen this behavior twice since then, and I’m at a loss. Does anyone have any idea what could be going on or how I can debug this? Thanks.

Instead of doing this, go to About -> Show log -> Live -> and set the dropdown to Profiling. You should see activity at that logging level even for seemingly “hung” backups.