My time Machine keeps saying, "Time Machine could not complete the backup. This backup is too large for the backup disk. The backup requires 345.74 GB but only 289.80 are available." I have already excluded files. I have a 1tb external drive. HELP!!!

Question

For over two weeks now I have been frustated and not having my TIme Machine back up to my 1tb external drive. I dont understand why now its a problem.  It keeps saying
"This backup is too large for the backup disk. The backup requires 345.74GB but only 289.80GB are avialable.  Time Machine needs work space on the bakup disk, in addition to the space required to store backups. Open Time Machine preferences to select a large backup disk or make the bakup smaller by excluding files." So I have already excluded almost all of my files, and even deleted the backup disk yet, that quote still keeps popping up. I am truly at a wall with this. I have a Mac OS X version 10.7.5. CAN SOMEONE HELP ME PLEASE????

Answer 1

If you have more than one user account, these instructions must be carried out as an 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. Click Utilities, then Console in the icon grid.
Make sure the title of the Console window is All Messages. If it isn't, select All Messages from the SYSTEM LOG QUERIES menu on the left. If you don't see that menu, select
View ▹ Show Log List
from the menu bar.
Enter the word "Starting" (without the quotes) in the String Matching text field. You should now see log messages with the words "Starting * backup," where * represents any of the words "automatic," "manual," or "standard." Note the timestamp of the last such message. Clear the text field and scroll back in the log to that time. Select the messages timestamped from then until the end of the backup, or the end of the log if that's not clear. Copy them (command-C) to the Clipboard. Paste (command-V) into a reply to this message.
If there are runs of repeated messages, post only one example of each. Don't post many repetitions of the same message.
When posting a log extract, be selective. Don't post more than is requested.
Please do not indiscriminately dump thousands of lines from the log into this discussion.
Some personal information, such as the names of your files, may be included — anonymize before posting.