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 Trivia Question
This question has been bugging me (well, at least it's been unresolved :-)) for
the last FOUR years, and I just never thought to ask it on USENET! Could some
kind Ultrix sysadmin put me out of my misery and tell me just WHAT THE HELL IS
IN THE FILE /upgrade? Is it some top secret code that tells you DEC's
strategic plan? ;-)

Thanks very much.


 Tue, 05 Sep 1995 12:48:20 GMT   
 Trivia Question

If I remember correctly it's a license file which contains the number
of concurrent Ultrix users you are licensed to run, but only on
pre-4.0 systems. With 4.0, this function was moved to lmf, and there
is no need for that file.


 Wed, 06 Sep 1995 08:37:52 GMT   
 Trivia Question

In article <1993Mar19.044820.6...@Princeton.EDU>, (Kartik Subbarao) writes:

        In the beginning UNIX was a trademark (and trade secret)
        of some entity of AT&T that kept changing every few years.
        And for a long time the only way to get UNIX was to get
        a source license from AT&T.  If your target was a system
        supported by the distribution of that particular UNIX,
        then life was good and you could pretty easily support
        as many users as you wanted.  If that source didn't support
        the target system you had to do the port yourself.

        But then people wanted to resell UNIX in a binary format
        and so AT&T invented a suitable set of the licensing rules.
        They still offered a source license, which was fairly expensive
        ($60,000+) for a commercial company.  They also offered per-user
        licenses for the binary system distributors.  The cost of the
        license was tiered to the number of users allowed.  A two user
        license was much less expensive than a 64 user license.

    The author becomes cynical...

        Clearly, to keep the AT&T City of Lawyers (now idle after their
        battle with the U.S. Government over the Break-Up) happy that
        license limits were enforced, vendors had to find ways of checking
        the number of users.

    Enter ULTRIX stage left.

        ULTRIX V1.0 was pretty directly derived from 4.2 BSD.  In order
        to use 4.2 BSD you needed a source license and thus user limits
        were what the machine would support.  ULTRIX on the other hand,
        needed to check and enforce the user limits.  In order to allow
        for different user limits, some mechanism had to be used to allow
        changing the limit.

        The limit was tied to the QUOTA structure used as part of the
        disk quota (which is why QUOTA in the configuration isn't really
        an "option").  In order to allow changing the user limit different
        versions of machdep.o were provided when recompiling the kernel.  
        This method worked, but was very painful.  If machdep ever changed,
        as part of a new version, all the user limit variations would have
        to be created and distributed.  That distribution required keeping
        track of who bought what upgrade and making sure they got the
        right (new) machdep.o.  This often failed.

    The introduction of /upgrade.

        I believe it was in ULTRIX V2.0 that a new scheme for the
        distribution of user limits was introduced.  One version of
        machdep.o was produced that kept the user limit stored in a
        format/location only it knew.  A program was provided that
        could write a value where machdep.o expected it and this value
        was read from /upgrade.  Thus, the same /upgrade could be
        used on every version, simplifiying the distribution.

    The semi-retirement of /upgrade.

        With the intoduction of the License Management Facility in
        ULTRIX the scheme was changed again.  I think this was in
        ULTRIX V4.0, but may have been V3.x.  In order to support
        the old /upgrade scheme, the program that read /upgrade was
        modified to create an appropriate LMF user upgrade license
        when the system initially booted.  This would end up in the
        LMF database and thus /upgrade would never be used again.

    On /upgrade...

        As for the format of /upgrade, I believe it was a 1 KB file,
        with the value for the user limit encoded in it.  It may have
        been encoded as a simple integer, relying on obscurity to hide
        the location of the value machdep.o used.  Still this would
        have allowed trivial modification of the 1 KB file to change
        the limit.  It may have been that at that point DEC didn't
        care if the CUSTOMER was in violation of the license agreement
        with AT&T.  We had tried to enfoced the user limit that the
        customer purchased, but the customer subverted it.  That would
        then be a matter for the City of Lawyers and the customer's
        lawyers to work out...

Alan Rollow                   

 Sat, 09 Sep 1995 06:55:46 GMT   
   [ 3 post ] 

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