VD - Virtual Disk Package

Virtual disks - carve up a larger disk into any desired number of
virtual disks of varied sizes.  The virtual disks do ANYTHING a
real disk can - you can intialize them, allocate, mount public,
BRU to and from, mount read only, and even crash (delete) them.
You treat them exactly like any other disk. 

FIRST A WORD FROM OUR SPONSOR:

This is a super package that is easy to use by anyone on your system.
It is great for cutting up large winchester disks into smaller
disks.  A great way to set up disk management.  Wish you could have disk
quotas like VMS.  Give everyone their own virtual disk of a predetermined
size - if they fill it up, that's it, they have to clean it up.
Wish you had subdirectories to group directories containing related
files?  Set up virtual disks as the head directories.  One for
V3.0 sysgen, one for V2.1 sysgen, one for Seattle applications,
one for test applications, etc.  Problems with people using the
same directory for different uses?  Give each one a virtual disk,
then they can use any directory they feel like and never bother
the other.

Just for big machines?  No way.  It is ideal for the Micro-11 systems.
We cut up our RD drive into several disks.  Only the system files
are accessed from the physical drive DU:.  All other files are accessed
from virtual disks.  No worry about filling up your system disk and
crashing the system.  All users should be working on virtual disks,
and no one on the "system disk".  Its great for backups to.  Stuck
with floppys for backup?  Backup your virtual disk each on a few flops as
needed, and the "system disk" on a few flops (excluding the virtual
disk files).  No need to ever backup the whole disk again.

Hard to implement?  Nope.  If you have access to your sysgen work files,
you can build the VD tasks.  The VD driver is loadable and so no need
for a new sysgen.  

Reliable?  This package is getting so mature, that we have not encountered
any bugs for ages.  We haven't even found many "features" lately.

Get the feeling we like Virtual Disks?  You bet.  They are an ideal
package for RSX systems.


AND NOW BACK TO THE NUTS AND BOLTS:

The Virtual Disk package in use at Cargill is derived from sources
on various DECUS RSX SIG tapes, plus a few of our own enhancements.
Thanks to Ralph Stammerjohn, Glenn Everhard, and Ken Cross for
99 percent of the work.  

This version allows nested virtual disks (create a VD on another
VD), with protection if the 'parent' disk is dismounted. It 
also allows creation only if the user knows a special switch value.
Finally, it uses Ken Cross's AVD, which picks the next available
VD unit for any allocation request. This makes it super-easy for
non-wizards to use VDs.

We have been using most of the package unchanged since RSX-11M V4.
This release has been updated to work with RSX-11M-PLUS V2.1, and
transferred to V3.0 with no modifications required.
No problems have been encountered when running 
under Update A or Update B.  We run EVERYTHING on our system
from VD except RSX itself, and each user's login.cmd file. 
It works. It is extraordinarily useful. Try it. 

A sample command file has been supplied as an example that will
build the Virtual Disk package if certain required files normally
found on your sysgen work disk are on device LB:

The command file is VIRTDISK.CMD.  You can try running it as it
creates nothing outside of the current default UIC and deletes 
no files anywhere.  It also serves as documentation of what happens
where and what sysgen files are required.

In addition, we have included a command file VD.CMD and its associated
table file VDTABLE.TXT that we use for mounting and dismounting
virtual disks using a two letter code for each disk.  VD.CMD is
kept in the default command file UFD (LB:[3,54] unless otherwise
chosen at sysgen) so it can be accessed by all users, and the table
in LB:[1,5].  The system manager can edit user VDTABLE.TXT to add or
delete virtual disk entries.  The end user, can use VD.CMD to work
with virtual disks and does not need to know any information about
where the container file is located or the volume id, etc.  Type
"@VD ?" for futher help text.  You can run VD on this UFD if desired
to see help.


Directory:

README.VD -- this file

WIZARD.RNO -- installation and manager's notes for VD
GUIDE.RNO -- users' guide
GUIDE.DOC -- users' guide run thru RNO and in ready to print form
INIT.RNO -- notes on packing MANY VD container files on a real disk

VIRTDISK.CMD -- command file to build VD driver and AVD,DVD utilities

AVD.MAC -- Allocate Virtual Disk (AVD) Macro-11 source
AVD.TKB -- AVD task build command file
DVD.MAC -- Deallocate Virtual Disk (DVD) Macro-11 source
DVD.TKB -- DVD task build command file
PIPMAC.MAC -- common sources for AVD and DVD

VDDRI.MAC -- VDDRV sources
VDDRV.TKB -- VDDRV task build file
VDTBL.MAC -- VDTAB sources
VDPRE.MAC -- common sources for VDDRV and VDTAB
VDSYM.MAC -- common sources for VDDRV and VDTAB

VD.CMD -- example command file for convenient VD access by users
VDTABLE.TXT -- example VD availability table used by VD.CMD


If you have any questions, comments, enhancements or bug fixes, contact:

Jim Bostwick
AMI/Research Building
Cargill, Inc.
Box 9300
Minneapolis, Mn.  55440

612-475-6264


