topic Re: Preferred Mount - Shadowing in Operating System - OpenVMS

Preferred Mount - Shadowing

Chris O — Tue, 05 Jul 2005 12:10:24 GMT

We have a number of systems with dual-redundant HSx controllers. The drives on them are Phase II(host based) shadowed. We usually try to split the shadowset members between controllers. From a performance standpoint, is it better to have both members of a given shadowset on one controller or have them split between controllers? Thank you, Chris

Re: Preferred Mount - Shadowing

comarow — Tue, 05 Jul 2005 13:07:03 GMT

Yes, you are on the right track.
Not only splitting controllers will improve performance, but provide greater redundency.

Good job.

Re: Preferred Mount - Shadowing

Eberhard Wacker — Tue, 05 Jul 2005 17:48:16 GMT

Besides the redundancy advantage you have in general you have to set the preferred ways of your shadowset member disks explicitly (one to controller A and and one to controller B) to take advantage of your environment And this should be done on a regular basis to reset realtime changes after a contoller restart and such things.
Cheers,
EW