Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!ncar!tank!mimsy!haven!adm!smoke!gwyn
From: gwyn@smoke.BRL.MIL (Doug Gwyn )
Newsgroups: comp.unix.wizards
Subject: Re: questions about File System Switch
Keywords: File System Switch FSS
Message-ID: <9171@smoke.BRL.MIL>
Date: 14 Dec 88 07:21:50 GMT
References: <352@siswat.UUCP>
Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 33

In article <352@siswat.UUCP> buck@siswat.UUCP (A. Lester Buck) writes:
>Is FSS fully documented in some AT&T manual?

I think you have to look in the source code if you want to
develop your own filesystem type.  (I'll be happy if I'm
wrong about that.)

>What release of System V introduced FSS?

Release 3.0

>Is it always there, or is it a vendor option that can be
>left out?  (I only have S5R2 experience.)

I don't think vendors HAVE to include it under SVR3 licensing
provisions, but it would be pretty foolish to deliberately
remove it.

>Is adding a new filesystem on the same level as adding a
>device driver to the kernel?

Pretty much.

>For example, can a binary site use some type of link kit to
>add filesystem routines without source code?

I think it would be possible to support this, but I don't
know whether vendors will.

>I was wondering about adding a CD-ROM filesystem, which has an
>ISO or High Sierra standard format and a 2K physical blocksize.

That's actually a good idea.  Note that Apple did this in their
GS/OS, which has the moral equivalent of FSS.