My impression is that there are still some unpredictable corners in the time machine envirionment. I am running time machine on 5 computers at home (2 mac minis, 1 mba, 2 iMacs of different generations) all on Mavericks 10.9.2. Except one iMac with an external drive all time machine backups use time capsules (on the latest sw revision) from 2nd to the 4th generation. Four of these machines backup correctly every hour when active. Only on 1 mac mini that is configured as a server (on the latest sw revision) the backup only works occasionally and after my manual stop and start. The backup goes to a 3rd generation time capsule but I also tried a 4th generation device which showed exactly the same behaviour.
I tried out all the valuable tips in this stream including several complete resets and deletions of the backup sparsebundle but the problem staid. I monitored the backup in the log file but also with opensnoop -n backupd. There is nothing special neither in the log nor in the opensnoop trace except that in some cases backupd just stops. opensnoop doesn't show anymore opnening files and the process is stuck there for days.
Once I stop the backup and restart (sometimes several times) time machine runs as it should and completes the backup. Below I attached 2 opensnoop traces. The first one that got stuck in preparing and the second one that worked normally. The process always stops at the same position after having openend the file with the exclusion list. I am running out of ideas where to look at. Maybe one of you has an idea.
The trace that got stuck in "Preparing":
0 31466 backupd 5 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 31466 backupd 5 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 31466 backupd 5 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 31466 backupd 5 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 31466 backupd 5 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 31466 backupd 5 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 31466 backupd 5 /Users
0 31466 backupd 5 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 31466 backupd 5 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 31466 backupd 5 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 31466 backupd 5 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 31466 backupd 5 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 31466 backupd 5 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 31466 backupd 5 /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/OSServi ces.framework
0 31466 backupd 5 /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/OSServi ces.framework/Resources
0 31466 backupd 5 /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/OSServi ces.framework/Resources/Info.plist
0 31466 backupd 5 /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/OSServi ces.framework/Resources
0 31466 backupd 5 /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/OSServi ces.framework/Resources
0 31466 backupd 5 /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/OSServi ces.framework/Resources/English.lproj
0 31466 backupd -1 /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/OSServi ces.framework/Resources/Base.lproj
0 31466 backupd 5 /System/Library/OpenDirectory/request-schema.plist
0 31466 backupd 5 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 31466 backupd 5 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
Success:
0 72118 backupd 4 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 72118 backupd 4 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 72118 backupd 4 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 72118 backupd 4 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 72118 backupd 4 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 72118 backupd 4 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 72118 backupd 4 /Users
0 72118 backupd 4 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 72118 backupd 4 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 72118 backupd 4 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 72118 backupd 4 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 72118 backupd 4 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 72118 backupd 4 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 72118 backupd 4 /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/OSServi ces.framework
0 72118 backupd 4 /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/OSServi ces.framework/Resources
0 72118 backupd 4 /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/OSServi ces.framework/Resources/Info.plist
0 72118 backupd 4 /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/OSServi ces.framework/Resources
0 72118 backupd 4 /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/OSServi ces.framework/Resources
0 72118 backupd 4 /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/OSServi ces.framework/Resources/English.lproj
0 72118 backupd -1 /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/OSServi ces.framework/Resources/Base.lproj
0 72118 backupd 4 /System/Library/OpenDirectory/request-schema.plist
0 72118 backupd 4 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 72118 backupd 4 /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.pl ist
0 72118 backupd 4 /.vol/16777226/22
0 72118 backupd 4 /.vol/16777226/22
0 72118 backupd 4 /Volumes/Time Capsule/machine_id.sparsebundle/.dat19b6.002
0 72118 backupd 4 /.vol/16777226/22
0 72118 backupd 4 /Volumes/Time Machine Backups/Backups.backupdb/machine_id/2014-03-16-010741
0 72118 backupd 4 /.vol/16777226/22
0 72118 backupd 4 /.vol/16777226/22
0 72118 backupd -1 /Volumes/Time Machine Backups/Backups.backupdb/machine_id/2014-03-16-114220.inProgress/Contents/PkgIn fo
0 72118 backupd -1 /Volumes/Time Machine Backups/Backups.backupdb/machine_id/2014-03-16-114220.inProgress/Contents/PkgIn fo
0 72118 backupd 4 /.vol/16777226/22
0 72118 backupd 4 /Volumes/Time Machine Backups/Backups.backupdb/machine_id/2014-03-16-010741