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From: CRAA055%UK.AC.KCL.CC.VAXB@AC.UK.UUCP
Newsgroups: comp.os.vms
Subject: How to do 'logical disks' ?
Message-ID: <8706200510.AA09048@ucbvax.Berkeley.EDU>
Date: Sat, 20-Jun-87 01:11:04 EDT
Article-I.D.: ucbvax.8706200510.AA09048
Posted: Sat Jun 20 01:11:04 1987
Date-Received: Sun, 21-Jun-87 03:49:34 EDT
Sender: daemon@ucbvax.BERKELEY.EDU
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Does anyone know a way to logically partition a disk volume within VMS so that
a user sees only those directories below a particular root and so that his
disk quota only applies to that 'logical disk' - ie he cant create files
anywhere else on the same physical volume?


For example:-

  Suppose I define a /SYSTEM wide logical name to be a root thus:-

    ASSIGN/SYSTEM/tran=(concealed,terminal)  dua0:[PHYSICS.] KCL$PHYSICS


  and my users UAF entry consist of

    /DEVICE=KCL$PHYSICS    /DIR=[SMITH]


  Then the user would see a default directory at login of:

    KCL$PHYSICS:[SMITH]

  which would really be:

    DUA0:[PHYSICS.][SMITH]


All is good so far, the user has a logical disk set up which can be physically
moved to another disk, totally transparently to the user, simply by copying
the files and reassigning the logical name.


HOWEVER there are two problems, one minor and one major:

Minor: The users disk quota has to be duplicated on the new physical disk if
the files are moved. An inconvenience which a bit of DCL could probably solve.


Major: Because the users disk quota applies to the physical volume and not to
the 'logical disk' then, assuming he has access, it is possible to create
files outside of the 'logical disk' elsewhere on the physical disk volume. I
would like to stop my users creating files or looking at files outside of
their own 'logical disk'. How can this be stopped, if at all, other than by
denying access thru the normal file protection mechanism? bearing in mind the
possible need for moving the directory root to another physical volume, I dont
want to have to fiddle around with ACLs or file protections too much.


Im interested in doing this simply because I want to be able to segregate
different groups of users and be able to move those users around my disks
depending on the requirements of the group for disk space. Light users can
share a physical volume with others or be moved to their own disk as
requirements grow.

Of course if anyone has a better suggestion Ill be glad to hear it.


Regards,

Andy Harper,
Kings College UK

A.Harper @ VAXB.CC.KCL.AC.UK        [ EARN/BITNET/NETNORTH ]
A.Harper%KCL.CC.VAXB @ AC.UK
A.Harper%KCL.CC.VAXB @ ucl-cs.arpa    [ ARPA ]