VDDRIVER Step 2 for OpenVMS AXP V6.1 or later

Written by Glenn Everhart <everhart@arisia.gce.com>
Packaged by Hunter Goatley <goathunter@WKUVX1.WKU.EDU>

VDDRIVER is a Virtual Disk driver for OpenVMS AXP V6.1.  It uses contiguous
files on a disk to emulate additional disks.  For example, on a single
RZ25, you could create a dozen virtual disks using container files stored
on the RZ25.  The virtual disks (VDAx:) work just like normal disks and can
be any size.  The virtual disks can be MSCP-served to other nodes in a
cluster.

Building
========
To build VDDRIVER and the ASNVD program, just use MMK (MMS) if you have it,
or execute BUILD.COM.

	$ MMK	or	$ @BUILD

Using
=====
To use VDDRIVER, you must use SYSMAN to CONNECT the VDAx: devices:

	$ MCR SYSMAN IO CONNECT VDA0:/NOADAPTER/DRIVER=dev:[dir]VDDRIVER.EXE
	$ MCR SYSMAN IO CONNECT VDA1:/NOADAPTER/DRIVER=dev:[dir]VDDRIVER.EXE

The container files *must* be contiguous files.  You must also set the file
to /NOMOVE to prevent defragmenters from moving it.  You can use the
following sequence to create the disks:

	$ copy nl: disk:[dir]VDA1.DSK/ALLOCATE=XXXXX/CONTIGUOUS
	$ set file/end_of_file/nomove/nobackup disk:[dir]VDA1.DSK

The /ALLOCATE value indicates the size in blocks of the disk. You then use
ASNVDM6 to assign a VDAx: device to the container file:

	$ asnvd :== $dev:[dir]asnvdm6.exe
	$ asnvd/assign vda1: disk:[dir]VDA1.DSK

Once assigned, you can then INITIALIZE and MOUNT the disk:

	$ initialize vda1: test
	$ mount/cluster vda1: test

You can use ASNVD to disassociate the VDAx: device from the container file:

	$ dism vda1:
	$ asnvd/deassign vda1:

Once deassigned, the VDAx: device can be re-assigned or assigned to a
different container file.

The following command will show you the container file associated with a
VDAx: device:

	$ asnvd/report vda1: