[Info-vax] automatic shadow copy?

[Phillip Helbig undress to reply]

In article <4c1ad8c0-8e1d-4093-a1f7-6de459e16417 at googlegroups.com>, IanD
<iloveopenvms at gmail.com> writes: 

> I was under the impression that shadow members have to be specifically adde=
> d to the member set but when our system boots, the system disk shadow membe=
> r is automatically added and completes under a merge operation. Obviously s=
> hadow system disk is ticked in sysgen etc

One should never explicitly add members to the system-disk shadow set 
during startup.  Well, one can, but by that time the shadow set will 
already have been formed.  In my case, the system was up and THEN I 
physically inserted the disk and ran AUTOCONFIGURE.

> I cannot find any reference to the shadow member disk anywhere in any proce=
> dures we run so I'm guessing that this information is embedded somewhere on=
>  the primary shadow member itself and that vms is automagically adding in t=
> he second shadow disk member of the system disk when it boot?

For the system disk, yes.

> I thought this went against the recommendation that a system disk shadow me=
> mber should not automatically be added in case it's a last known good copy =
> then you have nothing to go back to? I think I read that somewhere

You boot from a physical disk.  Soon after, the other member, if found, 
is added.  You can list all members in BOOTDEF_DEV, so it will try all 
until one is found.

> Any doc source that I can read up on to explain this auto adding phenomenon=
>   would be great too :-)

The VMS documentation?