I have a mac mini that currently has osx 10.3. I want to upgrade it ultimately to Leopard (10.5). My problem is that the mini only has a CD drive and 10.4/10.5 seem to only come on DVDs. Is there a way I can create an install/upgrade disk on a flash drive to perform my install/upgrade? If there is a way to do it, would a 4GB flash drive work or would I need a larger flash drive?
My method was to use a freshly reformatted hard drive in an external USB enclosure, because I didn't have a large enough flash drive. It requires about 7.5GB (DVD-DL), so no, a 4GB won't work, but you can pick up an 8GB or use the external like I did. Follow the instructions at macinverse and it goes very quickly.
I'm betting this is a PowerPC based Mac Mini. I can almost guarantee those that shipped with CD-only drives were not Intel. An easy way to check is to see if you have an IR sensor on the front in the optical drive slot. If it's there, it's Intel, if not, PPC.
If it's PPC, you will probably not be able to use USB for booting this machine. Some PPC computers could boot off USB2, but it's slow and sometimes unreliable.
FireWire would be the best thing to use here. The instructions from maciverse mentioned above will work just fine with a FireWire drive too.