From: Chris_F_Chiesa@cup.portal.com
Newsgroups: comp.os.vms
Subject: Re: Splitting a user disk
Date: Mon, 14 Dec 92 18:22:25 PST
Organization: The Portal System (TM)

Ken Connelly writes: 

>  Split the current users on DUB0 onto DUB1 and DUB2.  A current (and
>  future) user will have diskquota and directory on *only one of* DUB1 or
>  DUB2.
>
>  For my convenience:
>
>    $ DEFINE/SYSTEM/EXEC/TRANSLATION=(CONC,TERM) STU1      MOE$DUB1:
>    $ DEFINE/SYSTEM/EXEC/TRANSLATION=(CONC,TERM) STU2      MOE$DUB2:
>
>  The default device in SYSUAF will be STU1 or STU2.
>
>  And to maintain the current logical STUDISK:
>
>    $ DEFINE/SYSTEM/EXEC/TRANSLATION=(CONC,TERM) STUDISK   MOE$DUB1:,MOE$DUB2:
>
>This *appears* to work, i.e., DIR STUDISK:[000000] shows all files in the
>MFD of both devices.  A bonus (I think) is that they show up as a single
>list, not as separate lists as seen with DIR SYS$MANAGER, etc.  Also, 
>DIR STUDISK:[some-valid-directory] lists the files in that directory as
>expected.
>
>Is there anything obvious that I'm missing?  Or worse, anything insidious? 
>Or is there a better way?

I apologize for including nearly Ken's ENTIRE posting, but I could't iden-
tify any "chaff" that could be left out...

Up until last week, all of my users were in the [000000.USER.username] 
directories of my system disk.  A rooted logical name of SYS_USERDEVICE
pointed to [000000.USER.], so that [000000.USER] appeared as 
SYS_USERDEVICE:[000000], and UAF "device" fields specifying SYS_USERDEVICE 
so that logging in as any user and doing a DIRECTORY gives you

   Directory SYS_USERDEVICE:[username]
     ...files...

When I split the users into the [USER.username] directories of TWO disks,
much as Ken describes above, i.e. two rooted directories SYS_USER1 and 
SYS_USER2, and SYS_USERDEVICE now a search-list of SYS_USER1,SYS_USER2, 
I too found that I could do a DIR SYS_USERDEVICE:[000000] and see a single
list of the username.DIR directories on BOTH disks, transparently alphabe-
tized and listed.  I could also do a DIR SYS_USERDEVICE:[username] and see
the contents of any user's top-level directory regardless of disk.  The
users could still log in and see

   Directory SYS_USERDEVICE:[username]
     ...files...

as before.

HOWEVER!!!  Users whose directories resided on SYS_USER2: could not create
new files in their own directories if they referred to them by SYS_USERDEVICE,
only if they explicitly used SYS_USER2 instead.  Editing new files into exis-
tence suffered similarly.  Apparently file-creation doesn't handle the combi-
nation of search-list-of-rooted-logicals properly.  Since all the users'
UAF entries specified SYS_USERDEVICE, their default directory specification
contained the "non-working" reference, and I had to go through the UAF by
hand and change all SYS_USERDEVICE references to SYS_USER1 or SYS_USER2 on
a per-user basis.  I was hoping to keep the "split" totally invisible by
keeping everything hidden under the blanket of SYS_USERDEVICE, but that 
appears to be impossible.  Ken, you presumably won't have problems since 
you've explicitly entered STU1 or STU2 in your UAF also, but it seems a pity
that this should be necessary.  I'd appreciate any tips on making a "split
disk" truly transparent to the user, but I suspect it may be impossible...

Chris Chiesa
  Chris_F_Chiesa@cup.portal.com