Have you checked the Time Capsule drive to see how much space is left on it? You can see free space in this screen in Airport Utility.
Just to confirm, you are referring to Apple's Time Capsule router/backup combo device yes?
I started by freshly erasing the Time Capsule drive using Airport Utility, so roughly the full 3 TB is available.
sudo mdutil -E /
Hmmm... okay. So after formatting when you try to backup a 2TB drive you are getting the full error?
Let's try a couple things.
command-r boot to recovery then start Terminal from the Utilities menu. Now type resetpassword (all one word) in the Terminal window and hit return. You will get the window below. Select your user name in the drop down then click reset in the lower right.
Go ahead and quit Terminal then launch Disk Utility while still in recovery and select your disk then click repair disk. When it is done reboot back to normal mode.
Now start Terminal and paste in the line below and hit return to rebuild the Spotlight index. You will be asked for your password. Wait for the Spotlight reindex to finish then try a new Time Machine backup. Time Machine uses this index to ID files, so this may help.
sudo mdutil -E /
Thank you very much. I am leaving on a two-week trip tomorrow and due to the time it takes to complete a backup I won't be able to do this until I get back. I have one more question before I go.
The way that my iMac is set up is it has a 250Gb SSD and a 2 TB hard drive. In total they contain about 1.9 TB of data which I am trying to back up. Before Mavericks the backups ran smoothly onto the same Time Capsule I am having problems with, and since I installed Mavericks I haven't been able to complete a backup, even after erasing the Time Capsule and attempting to start over. (On all my other Macs, Time Machine continued as normal after upgrading to Mavericks.)
Since I've had the problem with my main Time Capsule I have been using Time Machine to back up just my 250GB SSD to an older, smaller capacity Time Capsule. That is working perfectly.
Knowing all that, do you think there is a problem specifically with my iMac's 2TB hard drive, and if so would that change the approach you outlined above?
That should not change anything, assuming the 2TB drive is okay. You should run a Disk Utility repair disk on that drive also.
I have seen several forum posts from users with this problem after a Mavericks upgrade, but everybody seemed to be okay after starting a new Time Machine backup (starting over).
Enjoy your trip and let me know how this goes when you get back.