My western digital mybook suddenly became read only. It won't record new timemachine back ups because of this. I used the disc utility to verify the disk drive and it told me to repair it. I tried but it said "Disk Utility can’t repair this disk. Back up as many of your files as possible, reformat the disk, and restore your backed-up files." So, is this disk drive shot? Its at least five years old, maybe more. The mac we have it hooked up to is only used for guests, games, quick internet stuff, nothing important. Time to throw this in the safe and move on? Also, if this is shot, thinking of moving my couple year old WD hard drive from main imac to this one and just getting a new one for the "good" imac. I'm just a little confused on storage space. If my imac has 2 TB of storage, how much more storage would I need to get for the new hard drive because doesn't time machine store multiple backups and therefore need more space then your computer has?