Re: UC07 with BA350/RZ28 disk spinup problem
- From: JF Mezei <jfmezei.spamnot@xxxxxxxxxxxx>
- Date: Mon, 01 May 2006 15:08:04 -0400
Hoff Hoffman wrote:
This controller emulates an MSCP storage Q-bus controller, and thus
these disks show as DU-class disk devices?
The SCSI Q-BUS controllers I have seen all emulate MSCP devices.
Remember that at that time, VMS did not have SCSI drivers (or its SCSI
drivers were very limited).
It is not clear if the Q-bus adaptor would tranmslate an MSCP "spin up"
command to a SCSI "spin up" command.
Even from the >>> console, one does not have access to the SCSI
commands, even less on VMS. One must "boot" the controller to get access
to the controller configuration, at which point you can issue SCSI
command directly from the controler.
OpenVMS itself sends the spin-up command.
up. DIGITAL drives have provided staggered disk spin-up sequencing back
as far as the DSA/RA series disks, and probably much further. On the
DSA/RA series, it involved a daisy-chained sequencing cable.)
Chicker-egg situation. VMS needs access to a spun up disk before it can
boot enough to send spin-up commands to the disk :-)
It would have likely been done by the KDA50 controller for instance.
Also, in the case of those BA350 boxes, does the box itself send totally
raw unedited SCSI commands to the disks in it ? Or is there some editing
done ? Since these boxes are able to force a SCSI ID on drives, what
else do they do between the host and the physical disks ?
Is it possible that it is the box'es responsability to request a
disk-spin up ?
.
- References:
- Re: UC07 with BA350/RZ28 disk spinup problem
- From: Hoff Hoffman
- Re: UC07 with BA350/RZ28 disk spinup problem
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