Time Machine error. Unable to complete backup. An error occurred while copying files to the backup volume. Tried restarting, remounting external WD drive. Still cannot backup.

Either the problem is gone or else I've just bypassed it by what I did, but the past 2 days have been without problem.

I reversed the USB cable connecting the Buffalo external HD to my iMac and swapped ports on the hub. I also re-indexed Spotlight.. but I also removed the external HD from indexing. By the way I have two external hard drives.

TM hasn't reported any problems backing up successfully since then.

But there is this curious Error message in Console near the end of the backup process, each time it's been done in the past two days. If you don't mind looking at it, here is the error message within its context:

8/21/13 6:37:39.199 PM com.apple.backupd: Starting standard backup

8/21/13 6:37:39.318 PM com.apple.backupd: Backing up to: /Volumes/TMBackups/Backups.backupdb

8/21/13 6:37:43.438 PM com.apple.backupd: 327.3 MB required (including padding), 708.51 GB available

8/21/13 6:38:22.526 PM com.apple.backupd: Copied 2042 files (11.7 MB) from volume Macintosh HD.

8/21/13 6:38:22.720 PM com.apple.backupd: 313.2 MB required (including padding), 708.49 GB available

8/21/13 6:38:26.352 PM com.apple.backupd: Copied 625 files (33 bytes) from volume Macintosh HD.

8/21/13 6:38:27.204 PM mds: (Error) Volume: Could not find requested backup type:2 for volume

8/21/13 6:38:27.205 PM com.apple.backupd: Starting post-backup thinning

8/21/13 6:38:27.205 PM com.apple.backupd: No post-back up thinning needed: no expired backups exist

8/21/13 6:38:27.290 PM com.apple.backupd: Backup completed successfully.

Is all's well that ends well ("Backup completed successfully")?

David Strumsky wrote:

Either the problem is gone or else I've just bypassed it by what I did, but the past 2 days have been without problem.

Yay! 🙂

I reversed the USB cable connecting the Buffalo external HD to my iMac and swapped ports on the hub. I also re-indexed Spotlight.. but I also removed the external HD from indexing.

Yup, any of those could be it. Pick up a new USB cable or two, just to have around.

8/21/13 6:38:27.204 PM mds: (Error) Volume: Could not find requested backup type:2 for volume

I see that occasionally, too, and in logs posted in these forums. Don't know what it means, but I suspect it has to do with whether or not there's a Local Snapshot matching a backup. Doesn't seem to be a problem, though.

Is all's well that ends well ("Backup completed successfully")?

Usually. If something makes it run very slowly, but it eventually finishes, it's considered normal. And sometimes if it has trouble deleting expired backups, or if you cancel at that point, or during the monthly verification of a network backup, it will still show "normally", since the actual backup has been completed, but some of the "housekeeping" didn't.

Thanks, that is a common problem for sure. 🙂

That Pondini article just helped very much. I had been having problems for months. I should have dug sooner.

I don't think Time Machine is cantankerouser (to coin a word) than other backup programs. In fact, I still think it's excellent.

Thank you!