Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!lll-winken!uunet!dg!rec
From: rec@dg.dg.com (Robert Cousins)
Newsgroups: comp.unix.questions
Subject: Re: Unix deficiencies/problems
Message-ID: <159@dg.dg.com>
Date: 3 May 89 15:08:08 GMT
References: <810038@hpsemc.HP.COM> <810046@hpsemc.HP.COM>
Reply-To: rec@dg.UUCP (Robert Cousins)
Organization: Data General, Westboro, MA.
Lines: 39

In article <810046@hpsemc.HP.COM> gph@hpsemc.HP.COM (Paul Houtz) writes:
>gph@hpsemc.HP.COM (Paul Houtz) / 10:37 am  Apr 18, 1989 /
>
>I wrote:
>>   I am interested in peoples opinions of deficiencies or problems with 
>>unix.  . . .  
>  One thing I would categorize as a deficiency is the UNIX file system's
>inability to span disc drives.   In otherwords, your file system is limited
>to the size of a disc drive.    If you want more files in that file system,
>you must re-create it on a larger disc drive, or, if you already have the
>largest available, you must start putting files in multiple file systems.

>  To correct this:  Allow the disc address to be part of the address of
>the file, this way, you would only need one file system per Unix system,
>and that file system would have as many drives as it needs.   It would 
>simplify matters greatly.

DG/UX version 4.x has this improvement already.  Specifically, file systms
are made up of logical pieces which can be on any number of devices and
can be dynamically added.  If you run out of space, just add another
piece from some available device on the system.  Furthermore, the
block arithmetic is done in 48 bits so that you can support VERY
large file systems.  

The real problem with hugh file systems is that it is so easy to
have them corrupted.  The solution is for the file system to 
duplicate the allocation information in system related blocks so that
a file system rebuild can be done quickly and easily with little
or no loss of information.  THis info should contain a time stamp
for added dependability.  This is what DG/UX does.


>Paul Houtz
>HP Technology Access Center

Robert Cousins
Dept. Mgr, Workstation Dev't

Speaking for myself alone.