Time Machine in Yosemity? Beachball!!

Question

Why oh why is the yosemity incarnation of time machine bringing my macbook pro to a grinding halt? Nowadays it takes the program hours to backup a measly 35Mb while presenting me with the dreaded spinning beachball for minutes at an end.
The program is still as useful as ever, a real livesaver, but to have it running an actual backup surely annoys me.
It seemed the pre yosemity backups were incompatible so the hd was reformatted so it was a fresh start with the new operating system
Within a week the slowdown was so bad i threw the backup file in the trash. Deleting it took about a day, it contained millions upon millions of files. Total amount of data was only about 150 Mb.
I guess the cleaning up phase in the latest version doesn’t really clean up.
Please mr. Apple, fix this once so useful program. Or even better, return to the old Apple tradition of releasing stuff when it’s ready, and not because the calendar says it’s time.
With kind regards,
P. Keizer.

Answer 1

When you have the problem, note the exact time: hour, minute, second.  
These instructions must be carried out as an administrator. If you have only one user account, you are the administrator.
Launch the Console application in any of the following ways:
☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)
☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.
☞ Open LaunchPad and start typing the name.
The title of the Console window should be All Messages. If it isn't, select
          SYSTEM LOG QUERIES ▹ All Messages
from the log list on the left. If you don't see that list, select
          View ▹ Show Log List
from the menu bar at the top of the screen.
Each message in the log begins with the date and time when it was entered. Scroll back to the time you noted above.
Select the messages entered from then until the end of the episode, or until they start to repeat, whichever comes first.
Copy the messages to the Clipboard by pressing the key combination command-C. Paste into a reply to this message by pressing command-V.
The log contains a vast amount of information, almost all of it useless for solving any particular problem. When posting a log extract, be selective. A few dozen lines are almost always more than enough.
Please don't indiscriminately dump thousands of lines from the log into this discussion.
Please don't post screenshots of log messages—post the text.
Some private information, such as your name, may appear in the log. Anonymize before posting.