[vcf-midatlantic] vax scsi questions

VAXman at tmesis.org VAXman at tmesis.org
Mon Oct 9 09:06:59 EDT 2017

william degnan via vcf-midatlantic writes: 

>>> >
>>> >Guessing there us a way from the >>> prompt to change a drive's volune,
>>> >but I did not find a way to do it.
>>> From the dead sergeant, you can select a boot device.  Volume information
>>> --
>>> label, structure, ownership, etc., etc. -- are manifestated in the
>>> operating
>>> system (VMS).  If you had an issue with the device on SCSI id 2, you could
>>> have physically removed that drive.  The device would then not appear in
>>> the
>>> device configuration and the MOUNT command would fail:
>>> %MOUNT-F-NOSUCHDEV, no such device available
>>> Assuming there is no ON ERROR in the startup procedures, your system
>>> should
>>> then boot through the system startup to the point where you can login.  At
>>> that point, you can reconnect the device and issue:
>>> Then, a:
>>> should show you your disk devices including the device at DKx200:.
>one last thing...I only had one bootable drive, and I could only get to the
>$ prompt from the drive that was configured to mount and load some stuff
>from the ID=2 drive.  What you suggest above would work, but would still
>have to have done what I did to get into minimal boot, etc.  At least in
>VMS 5 minimal boot does not mount nor include any other drive than the boot
>drive in a $ show dev d.

Minimum boot will not execute your system's SYSTARTUP_VMS (or *_V5 because
you're living in the past).  That is, typically, where one would add MOUNT
commands to mount other device volumes available to the system.  When you
DO startup the system minimally, there are many other aspects of *normal*
VMS startup that are also bypassed.  You can also modify the system startup
in SYSGEN when you boot conversationally (>>> BOOT/[R5:]1) and define the
startup to the OPA0: (SYSBOOT> SET/STARTUP OPA0:).  WHen your system boots,
it will leave you at the DCL prompt ($).  No need to even know the SYSTEM
password or login to the SYSTEM account.  However, when you do this, there
is no error handling!  A error, even a typo precipitating an unknown command
syntax error, will kick you out with no resolve other than to reboot.  The
trick here is to issue a "$ SPAWN" command first.  This way, you'll have a
subprocess that, if it terminates, will dump you back into the STARTUP pro-
cess.  NOTE:   If you change the startup, you will want to change it back.

On my systems, I MOUNT volumes in a procedure (I call SYSTARTUP_MOUNT.COM)
that I run as a detached process.  If it hangs up on a MOUNT I can still,
eventually after STARTUP.COM and its scion complete, login.

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