Path: utzoo!attcan!uunet!bellcore!att!pacbell.com!ucsd!swrinde!elroy.jpl.nasa.gov!sdd.hp.com!hplabs!otter.hpl.hp.com!hpltoad!hpopd!hpcpbla!mark
From: mark@hpcpbla.HP.COM (Mark Simms)
Newsgroups: comp.periphs
Subject: Re: Jukeboxes under Unix
Message-ID: <10080001@hpcpbla.HP.COM>
Date: 11 Dec 90 11:57:52 GMT
References: <2868@polari.UUCP>
Organization: HP Computer Peripherals Bristol, UK
Lines: 27

Hewlett Packard's support of magneto-optical juke boxes allows
transparent access to all surfaces in the system.  All surfaces may be
logically mounted at the same time.  Whenever access is required to a
given surface the correct disc is inserted into one of the drives.  The
advantage of this approach is that access is completely transparent to
users, other than in terms of performance.  The main disadvantage is
that if a lott of accesses are made to different discs, then performance
can be poor.

Interestingly, the explicit load/unload commands can be constructed on
top of this system if required.  A load would cause an unmount of
whatever was in the drive and a subsequent mount.  An unload would cause
just an unmount.  If you really wanted, you could even add locking
functionality so that only the loading user could unload or reload.

Mark Simms

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Opinions expressed are my own and are not intended to be an official
statement by Hewlett-Packard Company
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Name:         Mark Simms
Profession:   Software Engineer
Occupation:   Research and Development
Organization: Hewlett-Packard Computer Peripherals Division
Unix-mail:    mark%hpcpbla@hplb.hpl.hp.com
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