  Intermittent device configuration problems? 
 The Question is:
 
On a Microvax II running VMS 5.4-3 with 16mb ram and VMS is residing on a
RD54 with around 90,000 Blocks availible. The system when rebooted will not
pick it's resident TK50 tape tape (MUA0:) and will forget that DUA1 is aN
RD53. I have successfully boote
d the system off of the Diagnostic tape and and have reformated the drive.
When the system is rebooted off of the rd54 system disk the rd53 drive will
be there for a few system restarts. The only way to get the TK50 back is the
go in to sysgen and do an a
utoconfigure all and doing a write current,default to save the settings. I
will then have the tape drive back until I have to reboot it. So the big
question is would I be better off nuking the RD54 System disk and
reinstalling vms 5.4, 5.4-3 and utilmatel
y working my way up 5.5-2 w/ y2k patches. My experience from the Microsoft
Broken windows environment is this would be one of the first options.
 
 
 The Answer is:
 
  Your experience with Microsoft environment is not particularly applicable
  to OpenVMS -- expectations and assumptions can differ widely among various
  operating system platforms.
 
  Reinstallation of OpenVMS is generally only performed when a completely
  new version of the operating system is required for site-specific
  purposes, or in relatively rare event of a hardware problem that leads
  to a disk data corruption.  Corruptions of the operating system are rare
  events on OpenVMS.
 
  Assuming that OpenVMS is performing its typical autoconfiguration as
  part of the system startup (this can be disabled via various means,
  including setting STARTUP_P1 to MIN), then this problem initially appears
  to be broken or misconfigured hardware, possibly due to the differences
  in how signals are floating in the drive control wiring, a failing drive,
  power supply problems, or similar.
 
  Depending on the particular enclosure used for your particular MicroVAX
  II system, there are specific settings required on the disk controller
  for use with the RD54 (usually the RQDX3), and there are differing
  requirements on the drive unit selection mechanism depending on the
  enclosure.
 
  The two most common enclosures with the MicroVAX II series involve one or
  more BA23 enclosures, or the BA123 enclosure, though there are few of these
  systems using the BA200 series and later Q-bus enclosures.
 
  That you have two RD-series drives and a TK50 would imply you have the
  BA123 series enclosure, or multiple BA23 enclosures.
 
  The BA23 tends to lack sufficient power for multiple RD-series drives,
  and is usually only configured with one RD-series drive and an RX50 or
  TK50 drive.
 
  For information on configuring Q-bus controllers, please see the Q-bus
  configuration discussions here in Ask The Wizard, such as "MicroVAX 3500
  Q-bus and bootstrap questions?".
 
  The OpenVMS Wizard would recommend contacting your hardware support
  organization for assistance.
 
