I purchased a new Seagate 500 GB FreeAgent USB drive thinking I would simply clone my MacBook Pro's HD. I've done it in the past and it worked like a charm, but this time I thought I'd try Time Machine. I have never been able to get Time Machine to work wirelessly, so I basically gave up on it. When I plugged in my external drive and ran Time Machine it went for a couple hours (trying to backup about 300gb of data) then stopped with the following error: "Unable to complete backup. An error occurred while copying files to the backup volume."
I Googled "Time Machine Error" and there were tons of people with the same problem. This topic in Apple's Forums had several people complaining of the same issue.
I tried several suggestions like the following:
- Renaming my Backup HD to not include spaces in the name.
- Rename my MBP to not include odd character's in its name
- Delete the "in progress" file on the backup drive
- Reformat my external drive
- Check the drive for errors
- Reboot the OS
None of these worked. What I did next was look at the system log by launching the Console. It's not easy to read so I downloaded these two programs to help:
By looking at the logs through these programs it was obvious that I had one file that could not be copied for some reason. It was a mp4 file of a movie (A Few Good Men). I went to the Time Machine options and excluded that file, ran the backup again, and it worked like a charm.
A couple of things trouble me about this error. First of all, without downloading third party software the error message that Time Machine is of no use. I had no idea why my backup stopped. Secondly, why can't Time Machine just exclude that file and continue while notifying me, or prompt me and give me a choice to continue or not?
In any case I finally got my backup to work. I hope this helps someone.