backing up with a mounted server volume

[Dan Lester]

I do nightly backups with SD (awesome!), but I came in this morning to find a failed backup. The offending line in the SD log was

| 02:44:37 AM | Error | SDCopy: FTS_NS error for item: '/Volumes/hware' err: 22, Invalid argument\n

Tried manually initiating another backup. Same thing.

Now "hware" is a server outside my LAN that I had mounted. I do these mounts regularly, but I usually unmount them at the end of the day. I'm not religious about doing these dismounts. I do them just to keep my desktop clean.

But last night I evidently neglected to dismount it, and SD seemed to have a problem with that. I can't say that I've ever seen this problem before. I checked my backup disks -- they were fine, dismounted "hware", and the SD copy then proceeded flawlessly.

Is SD, in fact, not tolerant of having external servers mounted during a copy? Never ran into that before. Please excuse me if this is written up in a manual somewhere.