Regarding your mount question.
First let me say Welcome to HPUX and they have a great website for troubleshooting
www.itrc.hp.com, click on the Search button.
There is a /etc/fstab which contains all of the filesystems are mounted at boot time.
The filesystems that are OS related are usually in the root Volume Group. vg00. Here is a sample from one of my boxes, an N-class.
dev/vg00/root 258048 59277 186406 24% /
/dev/vg00/stand 199381 43184 136258 24% /stand
/dev/vg00/var 1638400 1229543 384245 76% /var
/dev/vg00/usr 1638400 649486 927158 41% /usr
/dev/vg00/opt 1024000 497291 493825 50% /opt
/dev/vg00/home 307200 8289 280271 3% /home
The one filesystem that should be new to you is
/stand, this is where your kernel is built and resides. Notice that the filesystem type is "hfs". HPUX kernels MUST reside on an hfs filesystem. I have 11.i boxes that are still hfs for the kernel. I had recently asked about if the kernel would ever be able to exist on a vxfs filesystem. They basically told me not for a while yet.
Whatever other filesystems that are in /etc/fstab should be considered to be backed up, as long as they are not NFS mounted from another box on your box. If they are it will appear as the following.
hostname: /some/dir/mounted /some/dir/mounted nfs rw,suid 0 0
If you can list your mounted filesystems with out breaking any company rules, give us a look...
If you company is buying the software, I would suggest Veritas NetBackup over Omniback or any other utility.
If you only have fbackup, it will serve well to backup your box.