Time machine "hung up" and won't finish a backup

Question

TM was working fine for me. But it has sat at the same place for almost 20 hours now. I have plenty of disk space. The progress shows it is stuck at 40.3MB of 145.9MB. An OSX update was installed yesterday, is that the reason? Any steps to get this back on track would be greatly appreciated! Thanks.

Answer 1

Normally, a long 'Preparing' session after an update is OK. If you take a look at the Console logs Time Machine is reporting that your backups need "deep traversal". That's fine. Time Machine knows what is wrong and how to fix it. Let it do it's thing. If you have alot if data, it may take quite awhile.
After your update to 10.5.5 Time Machine realized the system no longer matched what it looked like during the previous backup. So it has determined that it's earlier catalogue of what-should-be-where is 'untrustable'. So it is going to go item-by-item comparing the before and after of your system.
However, in your instance, it is simply taking too long and seems to have choked.
*Anti-Virus Software*
Running anti-virus software can interfere with the backup process. Either disable it altogether, or try the suggestion outlined here, “If you use third-party anti-virus scanning software and have issues, make sure your Time Machine back up folder (Backups.backupdb on the Time Machine disk) is excluded from virus scanning.” (http://support.apple.com/kb/TS1516)
*Reselect Backup Disk*
There is the possibility that the first backup after a major OS update will fail. The Console may report that the backup disk is ‘not owned by backupd’. Essentially, Time Machine no longer recognizes the backup disk.
Go to System Preferences --> Time Machine.
Click the "Change Disk..." button.
Select "None" and click "Stop Backing Up".
Now click "Choose Backup Disk" and reselect your drive again.
Close System Preferences and try backing-up again.
Let us know if this helps.