[weblacky]

First off I need you to trust the process and follow the instructions without changes and see what you get. You're over complicating it by making incorrect assumptions that is clouding the information that was told to you. 

You might be under the assumption that /usr means USER... it absolutely doesn't, it's one of the few required system folders for a UNIX operating system, similar to "C:\Program Files" in Windows OS.  I'm going to assume you meant user home directories which are in a totally different location, see below.

You're also under the assumption that all the mount points will be laid out under FX as partitions. That's not the case at all. FX has only one job to lay out a ROOT disk or an OPTION disk, it does not layout file system mount points!  You cannot use it like gparted in Linux or diskpart in Windows or whatever to specify volume to filesystem directory mount points.  It does not do that.  There is a separate graphical disk tool in Irix that you can use to do that job once you have a running operating system.  FX partitions the disk during OS install... it does nothing else. You WILL NOT SEE.  /USR, /OPT, /HOME, /BIN, /SBIN, etc as mount points all laid out in FX...that's not it's job!

Also do not use the auto option as it's not in the instructions, don't use it! it doesn't do what you think it will do.

If you say you want a ROOT drive then the largest volume becomes partition 0 which is mount point "/".... From which all other folders are automatically included!  It's the same as having one big C: drive in Windows.  "/" means the entire volume contains the entire OS file system, that's also meant to be bootable.  You cannot boot an operating system from an OPTION drive.

You do not need to establish an additional mount point unless you add another drive, additional to a ROOT disk, and wish that drive to be mounted at a ROOT file system point. If you have a 7 GB hard drive then you're going to allocate 7 GB, roughly, to the main file system...which holds everything!  It's only when you add an additional OPTION drive that you care about where you mount the additional drive space, in Windows you'd have another drive letter, and Mac you would have something /volumes/drive.  In UNIX you could obviously mount the drives file system to any folder under "/" you wish and it becomes linked to the overall filesystem. 

UNIX does not have drive letters like Windows. All file systems must integrate into the main file system hierarchy. You don't even have a main file system yet, that's a ROOT drive.  After you have a working ROOT drive, you can format an OPTION disk in the graphical desktop utilities and make it store the home directories at /usr/people ... which is where are all the normal user home directories are except for the root user (admin), the root user doesn't have a home directory there for a good reason.

The only places I could see you "mounting" an addition OPTION drive (or more than one OPTION drives) would be places like /usr/people, /opt/, or new folders under /, like maybe a /External_Drive or /Personal_Files.  Should those folders disappear (due to OPTION drive failure) the system would still boot and root user could still login to fix things.  If you mount the secondary option drives at critical / points, then if those OPTION drives ever fail, and the main ROOT drive is all that's available, the OS will not start and you will have lost pieces of your main file system permanently.  You should mount into less conspicuous folders that can survive failure while the main ROOT drive still operates.

Under no circumstances are you to add partitions to the partition layout. That's not how this works. You declare a drive as bootable (ROOT) and containing the entire OS volume or it's an OPTION drive to be mounted somewhere on the main / tree on an existing ROOT disk filesystem, you can't have it both ways. 

You must have at least a SINGLE ROOT drive, you must boot from that ROOT drive, the ROOT drive allocates all available space to the entire central system. That file system contains everything in the operating system including user home directories, /opt. /usr, /sbin, etc... It's all one volume there is no separation.  Additional hard drives (OPTION) can be added for additional space at specific points in the (ROOT disk) file system.

Please follow the instructions and get to the end of the process then look at what the result is. It will be a lot more evident than constantly modifying the instructions and running into issues. This is not a flexible process! The process that has been dictated to you is the process that the manufacturer intended.

Even if you don't understand what it is you're doing at this very moment, please follow the instructions as they are written until you're at a graphical login screen where you can now look around at a successfully installed operating system and play with things.

You can always reinstall later if there's something you needed to change.

Helpful stuff! Good guide too. A question, why would I repartition as [RO]OT when I'd want /usr/ to have the most space? Is it to tell the OS that it's booting from there? That's good and all, but when I try to create a /usr/ partition after [ro]ot ([ro]ot gives me 0,1,8,10) it erases root and now I'm left with just usr, swap, volhdr, and volume (1,6,8,10). Another note, when I would use [a]uto for the formatting, it chooses the formatting for [u]srrootdrive, with efs, raw, efs, volhdr, and volume (0,1,6,8,10). Can I still use [ro]ot while still allocating more space to /usr/? Unless having everything on root is recommended, usually when I set up my older computers I have only system stuff on C: while everything else is under a separate drive letter, and I'd like to follow that.