Time Machine wont start backing up

[Mkallevik]

I plugged my external drive into my mac, and told time machine to use it as a backup disk. Then time machine said that I had to erase everything on the harddrive. So I canceled, and backed up everything on my external harddrive. Then I told time machine to erase everything on the drive. Now time machine dont start backing up.

It says:

Oldes Backup: --
Latest Backup: --
Next Backup: --

What to do?

[megfilmworks]

I plugged my external drive into my mac, and told time machine to use it as a backup disk. Then time machine said that I had to erase everything on the harddrive. So I canceled, and backed up everything on my external harddrive. Then I told time machine to erase everything on the drive. Now time machine dont start backing up.

What to do?Look at Time Machine in the System Prefs and it may say Next Backup with a time in the future.

[Mkallevik]

As I said:

Next backup: --

Edit: Sorry, you answered before I edited the post.

[synth3tik]

Since you already got everything on your back up drive backed up. You can go into disk utilities and reformat the back up drive, then give it a go

[johny5]

Try right clicking the time machine icon and selecting "backup now".
good luck, I tried to get this working on 2 macs to no avail, it ended up thrashing one of my external HDD's so ive switched it off until apple fixes it.
Someone else can trial it, i dont have the patience!

[megfilmworks]

I had a next backup time in the future. 3:06...and at 3:06 and a few seconds it started merrily backing up with a progress bar. So far so good.

[Mkallevik]

Since you already got everything on your back up drive backed up. You can go into disk utilities and reformat the back up drive, then give it a go

Thanks. It worked. Time Machine is now backing up.

[Sora]

I plugged my external drive into my mac, and told time machine to use it as a backup disk. Then time machine said that I had to erase everything on the harddrive. So I canceled, and backed up everything on my external harddrive. Then I told time machine to erase everything on the drive. Now time machine dont start backing up.

It says:

Oldes Backup: --
Latest Backup: --
Next Backup: --

What to do?

I found this a bit weird, but I formatted my drive again and did a initial backup, but subsequent backups wouldn't work automatically. It kept saying "Next Backup: --"
That's when I realized that if I plug in my mac and then plug in the external drive it re-enabled automatic backup. It seems that automatic hourly backups are "power supply" dependent. Seems like a smart safety feature to have. I can't imagine what would happen if there was a power failure mid backup.

Try it out.