Im a network guy, and know very little about system administration. I would like to install PFSense and Monowall to 2 CF Cards, but not sure how they should be formatted (NTFS or FAT32) and volume size. Both of the cards are 8 gigs. I was also wondering if it would be a problem using physdiskwrite with -u flag for disks over 2 gig.
PFSense and Monowall are both based on FreeBSD (which is not Windows, not a Microsoft product, nothing like the aforementioned, does not use their file systems) and use UFS/FFS as their primary file system.
You should let their installers slice and format the "disks". The
physdiskwrite utility can write an image file to the cards, you have to override the safety mechanism with
-u as Chop has mentioned.
I suspect the correct answer is neither. You should probably follow the instructions for installing an embedded pfsence ( I assume the CF cards will go into some sort of headless box.)