I have a 2007 iMac, 2.8 GHz Intel Core 2 Duo with 500GB. Last week my hard drive died so I had to have it replaced. Luckily I use Time Machine with a 1TB external, partitioned so that the iMac backs up to a 500GB section, so the technicians were able to do a complete restore. However, upon returning home and trying to resume backing up, the backups have been failing, saying that there is not enough room on the external partition. I just erased the last backup and have no other backups on there now, so it's basically empty, but I still keep getting the message that it needs over 500GB (about 520 GB) to complete the backup. The iMac currently has 470 GB used. I've run "Verify Disk" for the external in Disk Utility, and excluded everything reasonable o try to reduce the amount being backed up, and I still keep getting the message that more space is needed. Ideas? FYI: I don't want to erase and reformat the external because the other partition has my music files.