Time Machine. Can't exclude disk I'm backing up to.

[lokiju]

Got this working! There was some "partial backup" or something along those lines file name on the TM disk. I deleted that and tried again and it finally worked! Must of been on there from a prior system I used to use this USB drive on.

This isn't so much a Lion only issue as it was the case before I upgraded to Lion and I was hoping it'd go away with the upgrade.

Maybe I'm just not understanding how it works correctly but when I turn Time Machine on it ask me to select a disk which I have to assume is a disk to back up to not the source I want backed up as I do not see my boot/OS disk as an option.

I select an external USB disk I have attached and when I go into options and exclude, I can exclude any other external USB disk but I cannot exclude the destination external USB disk I set to back up to in the first step.

It of course fails to backup as it says it doesn't have enough space to backup the combined capacity of my boot/OS disk and the destination 1TB USB disk.

I don't want to backup the external USB disk, I only want to backup my boot/OS disk to my external.

What gives?

 

[QuarterSwede]

TM won't backup the destination disk which is why you can't exclude it (it's already excluded).

 

[lokiju]

TM won't backup the destination disk which is why you can't exclude it (it's already excluded).

That leaves me scratching my head then. It tells me it can't backup because it requires 1.2TB of free space yet my boot/os disk is a total size of 120GB with only 62GB used. My external destination disk is a 1TB with 416GB free.

Why is it claiming it needs so much free space?

When I do a Time Machine backup from my 13" 2011 MBA to another external USB disk that's physically attached to my Mini, it works fine.

In that set up my MBA has a 120GB boot/os disk with 21GB used and the destination disk is only 120GB with 25GB free.

 

[lokiju]

Anyone see this and find a fix?