[net.os] Allocating filespace

haapanen@watdcsu.UUCP (Tom Haapanen [DCS]) (12/04/85)

So, we finally have net.os.  Three cheers to Andy Beals!

To get the ball rolling, I will pose the following question to the
readers of this newsgroup (I did not think this appropriate for
net.arch or other newsgroups in the pre-net.os days...):

I am familiar with the directory and inode structure on UNIX (4.2 BSD)
and with the directories and file allocation table on PC-DOS/MS-DOS,
so I have an idea of how a file is allocated disk space (and placed in
the right directory) on those systems.  

However, I am not familiar with VMS, TOPS-10, OS-9 or the UNIClones.
How do they go about it?  They all have hierarchical (sp?) file systems,
so there should be some similarities between some of them.  Right?

What are the tradeoffs between the different ways of doing this?  Can
someone enlighten me?

				   \tom haapanen
I'm all lost in the Supermarket
I can no longer shop happily
I came in here for that special offer
Guaranteed personality				 (c) The Clash, 1979

jimomura@lsuc.UUCP (Jim Omura) (12/06/85)

     OS-9 is much like Unix in that it's hierchical (that looks wrong to me
is it?), but we don't have much in the way of the conventions for root
directory names.  On a floppy system the convention is to have a 'SYS'
directory to hold the 'password', 'errmsg' and 'motd' files.  Utilities
go in 'CMDS'.  Both 'CMDS' and 'SYS' are contained files (not root dir's)
on '/d0'.  Floppies are generally named '/d0', '/d1', '/d2', etc.  I
think most hard disk users name their root directories '/h0', '/h1',
etc., although I've heard that some name theirs '/d0', etc. because
they are used to that name and it happens to fall easily under a good
keyboard combination (ergonometric nomenclature?).  There's no reason why
we couldn't call them '/usr', '/u', '/etc', etc., but generally it isn't

     One nice thing is that OS-9 has long has a standard disk format.
When the Color Computer OS-9 came out, it didn't conform to the standard
however, because Tandy had already established their format before they
decided to use OS-9.  As a result of this, many peoply have taken to
supporting 2 formats.  I support 3 formats.  My Color Computer, with
SDisk (a 2nd source descriptor/driver kit) and pcxfer give me OS-9
standard format, Color Computer OS-9, and IBM-PC--Oh yes, and Color
Computer BASIC too.  Funny, I forgot all about that one--4 formats.
If you'd like to see it, I could write a bit about exactly what the
format looks like on the disk.

                                      Cheers! -- Jim O.

James Omura, Barrister & Solicitor, Toronto
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