Not too long ago i purchased an extra internal 1tb seagate hard drive. I installed it and have been using it to back up my main drive via Time Machine. The drive has been acting strange and sometimes Time Machine hangs up while trying to make routine backups. So I ran disk utility and got a "invalid node structure" alert. I've purchased an external WD 2tb drive to back it up to...but this is proving difficult. I'm unable to directly move the files from one drive to another and using disk utility to restore the disk doesn't work either. My brief research suggests purchasing Disk Warrior and running it on the old drive. I'm wondering if the quirks of time machine is exasperating my efforts. Any suggestions?