[Info-vax] booting on a single disk from a shadowset

[Jan-Erik Soderholm]

Den 2016-02-11 kl. 16:38, skrev Tom Adams:
> I am looking into this because I was thinking about writing a system
> recovery SOP for a failed computer that has a good disk. (I already have
> a software-based recovery procedure, but it's more involved.  I was
> thinking a hardware-based approach could be better in some
> circumstances.)
>
> dsa0 has dka0 and dka100 as members with dka0 the master member.
>
> If I take down the system and disconnect dka0 and try to boot on dka100
> then the system seems to hang during the boot (but maybe I did not give
> it enough time).
>
> I am pretty sure that if I disconnected dka100 and left dka0 connected
> then it would boot OK, but I can't recall trying it.
>
> The question is: Is there a quick way to get the system to book as a
> shadow-set on dka100 when dka0 (the master member) is gone?
>
> That way, someone could just pull a good disk out of a failed ds10, pop
> it into a spare ds10 and boot to recover the system.
>

As far as I have seen, one can boot from either of the disks
in the shadow-set. And also setup defboot_dev so that it points
and will try both disks when (auto-) booting. That is part of
the point with using HBVS in the first place.

I think you should try both ways and see if there is a differnce.