Lately I've noticed that my Time Machine backups are taking a very long time. I recently replaced my boot drive, and I thought the problem might have been due to the way I reconnected the drive to the old backups. But this week I got a new external drive for backups, and started backing up fresh with it, and it's still happening. I only have 78 GB on my boot drive, and it takes over 30 minutes to do an incremental backup, even when the machine has been mostly idle.
Looking in my Console log, I see:
6/9/13 6:23:32 PM com.apple.backupd Node requires deep traversal:/ reason:contains changes|must scan subdirs|fsevent| 6/9/13 6:32:14 PM com.apple.backupd Copied 109610 files (17.3 MB) from volume Macintosh HD. 6/9/13 6:42:00 PM com.apple.backupd Copied 86516 files (3.4 MB) from volume Macintosh HD.
It's approximately the same number of files during every backup.
I have BackupLoupe, and examined what's in each snapshot. Lots of things in /usr, /Applications, /System, and /Library are getting backed up every time. When I drill inside, I see that everything that's being backed up repeatedly is a symbolic link.
They're not taking up much space, but I think this is what's making the backups take so long. Why is it wasting time on all these links?