[Info-vax] SET VOLUME/SIZE and DVE

[Bob Gezelter]

On Sunday, December 23, 2012 10:55:47 AM UTC-5, Phillip Helbig---undress to reply wrote:
> When using dynamic volume expansion, at some point I will have a shadow 
> 
> set where all disks have a logical size less than the physical size and 
> 
> will a) want to add another disk of the same (or larger) physical size
> 
> to it and b) increase the logical size to the physical size of the 
> 
> smallest member.
> 
> 
> 
> Does it matter if a) or b) is done first?
> 
> 
> 
> As an example, suppose I have a 36-GB disk with a logical size of 9 GB 
> 
> (previously formed by adding a 36-GB disk to a 9-GB shadow set then 
> 
> removing the 9-GB member).  I want to increase this to 36 GB in logical 
> 
> size and add another member.  Should I first issue SET VOLUME/SIZE then 
> 
> add the other member or vice versa?
> 
> 
> 
> Could it be that the shadow copy will complete faster if first the other 
> 
> member is added, since only the 9 GB in use will be copied?  If so, then 
> 
> it would be better to issue SET VOLUME/SIZE only after all members are 
> 
> in the shadow set.

Phillip,

See my presentation "Migrating OpenVMS Storage Environments without Interruption or Disruption" at http://www.rlgsc.com/hptechnologyforum/2007/1512.html.

- Bob Gezelter, http://www.rlgsc.com