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From: rb@ccird1.UUCP (Rex Ballard)
Newsgroups: net.micro.68k
Subject: Re: CD ROMs to use 68000 OS9 (file servers)
Message-ID: <394@ccird1.UUCP>
Date: Thu, 1-May-86 21:10:49 EDT
Article-I.D.: ccird1.394
Posted: Thu May  1 21:10:49 1986
Date-Received: Sun, 4-May-86 06:49:06 EDT
References: <808@ihwpt.UUCP> <1185@lsuc.UUCP> <994@amiga.amiga.UUCP> <821@ihwpt.UUCP> <798@ccird2.UUCP> <1053@amiga.amiga.UUCP>
Reply-To: rb@ccird1.UUCP (Rex Ballard)
Distribution: net
Organization: CCI Rochester Development, Rochester NY
Lines: 30
Summary: Much different.

In article <1053@amiga.amiga.UUCP> bruceb@amiga.UUCP (Bruce Barrett) writes:
>In article <798@ccird2.UUCP> rb@ccird2.UUCP (Rex Ballard) writes:
>>My guess is that the BIGGEST reason for using OS-9 in CDI is that
>>OS-9 is the ONLY system which has a TRULY sharable Remote File System.
>>[...]
>>
>>With it you can send an "open /usr/lib/libc.a" or whatever file name,
>>and the treat it just like a standard block mode file.  You don't
>>have to know anything about how the files are structured, how
>>they are stored, or what the format of the disk is.  [...]
>
>Have you noticed that this is just like the amiga RAM: device?
>As files are created, and deleted the RAM: disk memory is allocated
>and freed.  "Look ma, no sectors!"
>>[... other nice OS-9 features, some of which we may not have...]

Actually a RFS is quite different.  The RAM: device can treat
the hierarchy as it wishes, but the OS determines how to traverse
directories, index of index blocks, find the next block,...

In the RFS, the Driver determines all of this.  The index blocks
could be little endian, hashed, btree sorted, linked, indexed,
and or contain contigous blocks, but the OS wouldn't know.  When
it is asked to "read(1,1000)", the RFS will give it the
next 1000 bytes following current position in the file.  The host
OS will not know which block of the drive he just read, or even
how he got there.  Since the RFS is doing all the lookup, the
driver might have to give the corrent seek position, or possibly
do minimal deblocking.  The RFS server is the only one who will
know which block was read, or how he chose it.