Two externals, one has Time Machine, want to put CCC on other but getting UUID error

So I recently got an iMac and two Passports (2TB each). I wish to put Time Machine (and other data) on one of the 2TB Passports. On the other 2TB Passport, I wish to put Carbon Copy Cloner on it. I have already installed the first Passport and used Time Machine to back up on that drive. However, when I try to install the second drive and use CCC select the second drive as the destination, I get an error that says both drives have the same UUID.

I currently do not have anything on the second Passport (it is new). Should I reformat it, will that make it have a different UUID? Or is there a different (better) way to change the UUID without messing things up?

Also, after I have made the back up with CCC, should I disconnect the drive and not keep it hooked up to the computer? Or should it just remain connected at all times?

TIA

Hi and welcome.

Do you recall how the EHDs were formatted when you bought them? By which I mean were they already formatted for Mac use - Mac OS Extended (Journaled) - or were they dual purpose (Windows & Mac)?

When I purchase a new EHD, I nearly always reformat them even if they are "Mac ready" partly to be on the safe side and partly to get rid of any accompanying software such as security or encryption which takes up space and is of no interest to me.

If your first one works OK, fine; but I'd still check its format via Disk Utility. As regards the second one, why not reformat it - Mac OS Extended (Journaled). This should sort out the problem, I think.

As regards keeping them both mounted or not—I would say that Time Machine should remain mounted to allow background updating on the hour.

For CCC or other cloning software, my practice is to undertake smart backups on a weekly basis and so unmounting this EHD between updates seems sensible. Depending on your usage, even weekly CCC backups may be too generous.

Hope that helps. Please report back if problems persist or if you require further assistance.

Ian

WD Passport external hard drives are pre-formatted to NTFS. When you setup a drive for Time Machine it will offer to format it to HFS+. However, CCC does not offer to reformat the drive. Member IWT is correct.

I was more asking about the UUID of the drive. CCC was having an issue with identical UUIDs of the two Passports I bought. Both were pre-formatted with HFS+ for Time Machine.

However, I took IWTs advice and formatted one of the drives anyways, and it did change the UUID of that drive so that I was able to use both drives. One drive has Time Machine and data. The other drive is for CCC.

Thanks for all your help guys.

Great! Glad things worked out for you. Join us again if you need help; or just follow the Forums. Tons of issues & advice.

Ian