What Mac OS is the LCIII running? I ask becasue through at least OS 7.6 and maybe OS8.0, there is a 2GB limit to any volume. A 9-GB hard drive would need five partitions. I think that limitation went away between OS8.0 and 8.1
Drive Setup, in "Utlities" on a hard drive and on most system floppies of that era, will format and partition for you.
new one SCSI 9 GB with 80
Be sure to count pins, if necessary, before getting an 80-pin adaptor. I've installed several 9G Ultra-SCSI drives in old Beige G3 servers and they were 68-pin. Yes there are 80-pin drives but are probably not as common and the 50 and 68
Internal adaptors work but there can be limitations in computers with small form factors like the LCIII (we have a Performa 475--same case). The adaptors, applied traditionally the the end of the hard drive, add length to the drive and can mke it too big for the case.
There are other ways an adaptor can be accommodated by putting it in unexpected places. Example. get an adaptor that goes on the logic board SCSI connector to allow the use of 68- or 80-pin cabling all the way to the drive. There was a site that showed how to do this but it's down at the moment.
The following article could perhaps be of interest to you:
Apple HD SC Setup 7.3.5 is intended for SCSI hard drives from Apple only.
The downloadable Drive Setup 1.7.3 may be able to format some third-party drives as well.
Otherwise, a third-party formatting utility would be required (some examples are mentioned in the article above).
You mentioned that the OS is 7.6. Do you have the system CD (and an external SCSI CD-ROM drive)?
Do you have access to a System 7.6 Disk Tools floppy (or another startup diskette)?
Is another smaller (but functioning) SCSI hard drive available?
While it is possible (via a special technique) to use a Windows PC to create startup floppies and certain system disks from some disk images, a self-mounting image (such as the downloadable Drive Setup 1.7.3 .smi file) must be opened in a Mac environment. The best way would be to try to find another (working) pre-1998 Macintosh computer with a built-in floppy drive, where you could open files and create (and/or modify) floppies.
An Apple user group in your area/country (Italy?) could possibly help you locate suitable older Macintosh equipment.
Yes, if it is a System 7.6 Disk Tools 1 floppy with Apple HD SC Setup 7.3.5, it is for Apple SCSI drives.
You would have to modify a startup floppy to hold an appropriate third-party formatting utility (or possibly Drive Setup 1.7.3). The startup floppy could be a disk tools disk, or the downloadable Network Access Disk 7.5. Unnecessary files on the disk have to be removed in order to free enough space for the new utility. A working older Macintosh computer would be needed for such a modification.
An alternative could be if you were to find a small Apple SCSI hard drive, to be formatted through the existing Disk Tools floppy. A temporary operating system can then be installed, and the thus working LCIII could be used for floppy disk modifications et cetera.
We have over 400 older Macs and I have yet to get a 9 gig drive to work well with pre-G3 computers using an external SCSI enclosure. There is something about the drivers in the newer hard drives that does not 'play well' with older macs. 1 gig and 4 gig hard drives will behave quite nicely but they are hard to find. There is a recycler in Seattle that sells older mac stuff. They have adapters and assorted drives. None seem to work for making 9 gig drives 'Plug and Play' on older macs using the external or internal SCSI connectors.
If you can find an external SCSI hard drive you will have much better luck. If you can find a 4 gig drive instead of a 9 gig you will have an easier time configuring.
If someone has some magic bullet to use on the 9 gigs, that would be great. A local recycler has plenty of 9 gig SCSI drives from non-apple machines but Drive Setup does not support them.
One major problem with the larger drives is that if Drive Setup will not recognize the drive, it will not let you partition the drive into the smaller partions that will mount using older operating systems.
If you can find software called MountAnything, you can play with the configurations but that again is not plug and play. How much work do you want to spend on the drive you have instead of finding a smaller drive that will be plug and play?