[Info-vax] USB or SCSI TAPE

[Stephen Hoffman]

On 2014-09-10 13:12:02 +0000, Rod Regier said:

> The HP employee who wrote the USB device driver says on the topic of 
> boot from R/W USB mass storage:
> 
> "...it had been slipped in by Fred (Kleinsorge) a parting gift on
> |his way out.  I only have read only access to comp.os.vms.  Can you
> |post a note saying the official position is that USB booting is only
> |suppoted for the systems that have USB DVD's.  That is it and no one
> |will lift a finger to help beyond that.  There is no magic required to
> |boot a VMS system off a USB pen drive or disk drive.  You need to back
> |up a working system to the device and make sure that the boot block
> |gets updated.  That is it, for DVD's you have to set the sysgen
> |paramter write lock sys to boot.


Getting the USB DVD devices going wasn't as easy as it probably should 
have been.

As one of the other folks that was working with said unidentified HP 
employee back then, the flash drive bootstraps were unstable and 
success varied by the particular flash device.  That was likely some 
then-unresolved low-level differences lurked across various devices.  
Beyond the boot block write-lock setting, the boot blocks vary by 
bootable media type.  You can't block-copy a DVD over to USB, as the 
sector sizes differ.  You'll need to account for the target media 
you're booting when (re)writing the boot block.

This is for disk (and flash) boots, too.  Not tape.  USB DVD boots 
should work.  For bootstraps beyond that, you're on your own.

Some related details: <http://labs.hoffmanlabs.com/node/28>


-- 
Pure Personal Opinion | HoffmanLabs LLC