Time Machine deleting backups?

Question

When Time Machine is finishing taking a backup of my Mac, why does it delete something, maybe old backups, even if I have nearly 200GB free space on my external disk?

Answer 1

And now it's stuck with 18,9MB and canceled
6.4.2014 13.36.37,783 com.apple.backupd[1294]: Starting automatic backup
6.4.2014 13.36.37,895 com.apple.backupd[1294]: Attempting to mount network destination URL: afp://;AUTH=No%20User%20Authent@WDMyCloud._afpovertcp._tcp.local/TimeMachineBac kup
6.4.2014 13.37.06,076 com.apple.backupd[1294]: Mounted network destination at mount point: /Volumes/TimeMachineBackup using URL: afp://;AUTH=No%20User%20Authent@WDMyCloud._afpovertcp._tcp.local/TimeMachineBac kup
6.4.2014 13.37.06,099 mds[79]: (Normal) Volume: volume:0x7fd3e386f000 ********** Bootstrapped Creating a default store:0 SpotLoc:(null) SpotVerLoc:(null) occlude:0 /Volumes/TimeMachineBackup
6.4.2014 13.41.52,245 com.apple.backupd[1294]: Disk image /Volumes/TimeMachineBackup/Samu - MacBook Air.sparsebundle mounted at: /Volumes/Time Machine -varmuuskopiot
6.4.2014 13.42.13,441 com.apple.backupd[1294]: Backing up to /dev/disk2s2: /Volumes/Time Machine -varmuuskopiot/Backups.backupdb
6.4.2014 13.47.45,821 com.apple.backupd[1294]: Will copy (2,6 GB) from Macintosh HD
6.4.2014 13.47.45,845 com.apple.backupd[1294]: Found 1010 files (2,72 GB) needing backup
6.4.2014 13.47.46,251 com.apple.backupd[1294]: 3,51 GB required (including padding), 183,9 GB available
6.4.2014 13.52.22,072 com.apple.prefs.backup.remoteservice[1380]: assertion failed: 13C64: liblaunch.dylib + 25164 [38D1AB2C-A476-385F-8EA8-7AB604CA1F89]: 0x25
6.4.2014 13.52.22,090 com.apple.prefs.backup.remoteservice[1380]: assertion failed: 13C64: liblaunch.dylib + 25164 [38D1AB2C-A476-385F-8EA8-7AB604CA1F89]: 0x25
6.4.2014 13.52.22,332 com.apple.prefs.backup.remoteservice[1380]: Bogus event received by listener connection:
<error: 0x10aae4b50> { count = 1, contents =
          "XPCErrorDescription" => <string: 0x10aae4e60> { length = 18, contents = "Connection invalid" }
6.4.2014 13.56.31,228 com.apple.backupd[1294]: Cancellation timed out - exiting
6.4.2014 13.56.31,245 com.apple.backupd-helper[869]: XPC error for connection com.apple.backupd.xpc: Connection interrupted
6.4.2014 13.56.31,245 com.apple.backupd-helper[869]: Not starting scheduled Time Machine backup: Failed to send message to backupd
And yeah, that deleting takes hours (about 10 last time).