Time Machine fails to backup

Hi guys,

Hopefully someone can help me. I've tried to backup my macbook pro tonight using an external 1TB USB drive. I have used this several times before and even recently restored something through time machine.

Yet tonight when I ran the backup, it said

Time Machine could not complete the backup
Time Machine hasn't backed up your computer in 161 days
Make sure that your backup disk is available or open Time Machine preferences to select a new backup disk

I have 750gb of free space on the external drive I use for these backups
I have run Disk Utility which confirmed everything is OK on the disk

The backup seems to start working.... it progresses as such

1. start backup
2. scans 1.3million ish files
3. prepares the files
4. starts backup
5. gets to around 750mb of 75.6gb to backup
6. fails with the message above

I have googled a lot and cannot really find and answer for this. Many people say that time machines will fail after around 18 months - but this is just a normal USB Hard drive - not a proper time machine unit.

any ideas? I would rather not have to format the disk as I'd lose the current backups!

thanks

i have had to "start over" with time machine several times. just pray is doesnt go down during the backup.

Any external hard drive can be a Time Machine drive. The only requirement is for the drive to be formatted using the Mac OS Extended Journaled file system and the GUID partition scheme.

It sounds like one or more of your backups are corrupt. A corrupt backup won't restore properly. I suggest wiping that drive and start over. Or buy a new external hard drive and use it instead.

Thanks guys... That's what I feared.. Looks like a format and new back up then