How do I format my new SSD properly
I have Mac Mini, late 2012, OS X Yosemite Version 10.10.4 2.5 Ghz Intel Core i5, 16Gb Ram, Intel HD Graphics 4000
I've recently added a 240Gb SSD to the machine.
It's booting up fine to the original drive, but I'm struggling to get the SSD to mount.
I've tried to reformat it - then realised that there was a problem that appear to be that the disk had a MBR boot record, rather than the GUID that it needs, I download Gdisk which let me sort this - but when I get it partitioned it only seems to mount momentarily and never verifies correctly - I've had a disk filing system Error 8 more than once.
I've tried doing this in Recovery mode - no real difference, and in Internet Recovery mode (which won't let me do anything other than reformat both drives as a hybrid drive - which ideally I would like, but I'd like to be sure that my new drive works before I take the plunge of deleting my existing drive)
I've also booted into single user mode and used fsck -fy - which appears to check that the original drive is OK, rather than the new one (presumably because it's still booting to the old one)
Any suggestions. It's a SanDisk SSD btw - I've not had any problems with their stuff before, so I'm guessing it's OK, also it is visible from the disk utility app, and the SMART monitoring shows it as verified.
Suggestions please ?
Mac mini, OS X Yosemite (10.10.4), Late 2012