Been searching the threads for answers about the crashes with lion. I know it's not compatible but am asking if I can move back to Snow Leopard without losing what's on my Mac Pro (mid 2010) and MBP (2009). Was getting it to run for awhile using the program from an external but no longer.
You mean FCS2 not FCP2 I presume. I would stick to SL. Clone or image your system drives and do a clean install of OS and then FCS2 and do updates.
FCP always runs best with a clean install particularly an OS update. I always started with a new drive in my MacPro when updating OS & FCS so I could always ALT boot the old system. The laptop is more difficult but at least backup an image of the drive before formatting and starting again.
A little more information may be necessary. Mac Pro is running Lion on its main drive. Also have two other drives installed. One of them I wiped with the idea of installing SL and FCS with the assumption that I could reboot when I have the need for editing. Just tried that by shutting down and holding the 'C' while restarting. Wouldn't get past the gray apple. Waited five minutes.
I also have three externals, all with information I wish to keep. One of those has the FCS along with other programs I use. Up until recently all were working well.
Holding down the C key is for forcing boot from an optical disc. I have a MacPro with FCS 2 on one disk running SL. Disk 2 is partitioned into 2, with SL. FCS3 on the first partition, Lion and FCPX on the second partition, so three boot options.
To boot from a different disk or partition choose "startup disk" in system preferences or hold down the Alt key when you power on, that will give the option of which disk you would like to boot from.
I have no desire to run an OS which is newer that the software I need to run, it's just asking for trouble. If it works don't fix it.