How to format secondary hard drive without OS CD?

Hey,

Got a pretty strange problem here so bear with me.

Recently installed a second hard drive to accompany my SSD in my Macbook Pro by removing the optical drive and using an optibay to replace it. OSX recognizes it fine but the problem is it was my old Mac Hardrive so it still has OSX installed on it.

For this reason I cannot format it through disk utility because it won't allow me to unmount it (I think because OSX is installed on there). It wont let me simply move the files to the trash bin either.

I tried to reboot and now that doesn't work either, this isn't a major problem as I've got everything backed up safely on an external hard drive.

So basically what I need is some way to format my secondary hard drive from single user mode or something (which I'm in now).

I can't simply put in the OSX CD because I no longer have an optical drive (due to the optibay replacing it).

Any ideas?

I can think of two ways:

Buy an external DVD drive (They're fairly inexpensive).

Use Target Disk Mode. (That requires another Mac firewire to firewire)

Regards.

If you're using your SSD as a boot drive, you can go into Disk Utility (on the SSD) and select the new hard disk to format it. Most upgrade kits like that will give a rough "enclosure" for your swapped out superdrive, too. At least good ones.