Can't delete old Time Machine backups I changed hard drives for my Time Machine backup. I can't delete the backups on the older hard drive. I get an error code after I use "Move to Trash": -8072. It spends 45min deleting some 1,000,000+ files to end in error -8072. A google search didn't turn up the reason for the error.

Also, for some reason creating a backup on this hard drive locked all my other folders and subfolders. I can unlock them one at a time but this will take a while. Is there a faster way?
On Lion, you can use tmutil to clean things up properly.

To delete backups one by one (snapshot by snapshot).

sudo tmutil delete /Volumes/drive_name/Backups.backupdb/mac_name/YYYY-MM-DD-hhmmss


If you are sure you have selected the correct path, you can delete all backups from that one Mac by not passing in the time and letting it delete the entire folder:

sudo tmutil delete /Volumes/drive_name/Backups.backupdb/mac_name


The sudo command needs your password (and it won't echo to the screen, so just type it and pause to be sure you're dating the correct files before pressing enter).