No longer able to detect MBLD as Time Machine Backup


I preiviously backed up my 2008 Macbook (running Mountain Lion) onto a Seagate external HD.

After purchasing a MBLD 6TB I wanted all my back ups to be on the MBLD and use the Seagate for other stuff.

I changed the configuration of the MBLD to RAID and, after about 36 hours, managed to back up my MacBook onto the MBLD.

However, Time Machine wanted to alternate backing up between the MBLD and the Seagate. 

I removed the Seagate from the list of drives to back up to.

Now, even though I can connect to the MBLD as admin, browse the public folders - including the Time Machine Backup folders, and transfer small files to and from no problem, when I enter try to back up using Time Machine I get the error message - back up disk not available.

The MBLD is no longer in the list of back up drives to choose from. I also can’t add the MBLD to the list of back up drives. Weird, as I can see I’m connected to it.

Any ideas how I can fix this as at present I’m back to using my Seagate drive as the designated backup disk and my MBLD is effectively an expensive paperweight!

Many thanks.

Hello, try deleting the time machine backup from the MBLD.