[Info-vax] Nonexistent IDE/ATAPI disk, is online, file-oriented device, shareable, available to cluster, error logging is enabled.

[Michael Moroney]

JF Mezei <jfmezei.spamnot at vaxination.ca> writes:

>Michael Moroney wrote:

>> Rather than scan for potential devices and _not_ creating a UCB/device
>> if it finds nothing responding, for some reason it creates one anyway
>> but marks it as a "Nonexistent IDE/ATAPI disk".


>Perhaps the author of the DQ driver could chime in. But is it possible
>that they did this on purpose to allow hot swappable devices ? If the OS
>has already reserved the structures for a device at DQB0:, perhaps you
>could plug in such a device and the system would be able to use it right
>away. (just speculating here).

No, not necessary for hotswapping.  Consider USB drives, you plug in a
drive and by magic the device/USB gets created and you can start using it,
no need to pre-create any drives.  Also DUDRIVER (which I worked on) 
had to deal with messages that could be new drives, alternate paths for
an existing drive or something we already know about, as controllers or
cluster members came and went.

Also, IDE drives are not hot-swappable.