[Info-vax] Best way to get what I can off a failed VMS Disk?

[Phillip Helbig undress to reply]

In article <rn1ion$g57$1 at dont-email.me>, Chris Townley
<news at cct-net.co.uk> writes: 

> >> If you have a hobbyist license, you have a license for HBVS.  You need a
> >> new disk anyway.  So try to see if you can form a volume set.
> > 
> > volume set ---> shadow set
> > 
> 
> Yes - never done that. Just ordered 2 more disks, and reading the manual

Example:

$ MOUNT/CLUSTER/NOASSIST/CONFIRM DSA400 -
  /SHADOW=($110$DKA100:,$120$DKB200:) <label> 

This will give a -F- message, which is confusing, to say the least, but 
you can see the source and copy disk and confirm.

You do need to have allocation classes set up.  If I recall correctly, 
they are required for shadow-set members not for the original reason of 
allocation classes (dual-ported disks), but rather because of the length 
and/or format of the disk name.

Note that the members can be on different controllers or even different 
nodes.  In fact, that is a big advantage of HBVS, above being able to 
swap out disks on a running system.  You can reboot a node and have the 
shadow set continuously available.  You can even have the nodes 
separated by large distances (at least several kilometres).  The members 
don't have to be of the same physical size, and you can dynamically 
expand to larger sizes.

However, if you don't have allocation classes set up, you'll have to 
reboot.