"Gary L. Paveza, Jr." <[log in to unmask]> wrote:

>Does anyone know how many volumes can be added to a volume group?  We are
>going to attempt to add 32 more disks to ours (16 primary and 16 mirrors)
>bringing our total from 96 (48 primary, 48 mirrors) to 128 (64 primary, 64
>mirrors).  We do realize that this is an extremely large volume group, but
>it only contains one application.  We are working to split it up, but for
>now, we need this space :).
The maximum number of volumesets is 255...
The maximum number of volumes in one volumeset is 255...
The maximum number of volumes (TOTAL) on a given system is 255...
A mirrored disk requires (obviously) to volumes, so the maximum number
of mirrored pairs is <128 (today you cannot mirror the system
volumeset)...

We have funded a R&D effort to increase most of the above limits. This
will be submitted to a "future release of MPE/iX"...probably not
available until the mid '98 timefram (though release schedules that
far out are subject to change). The new limits will be *MUCH* higher
with one major exception. The maximum number of volumes in a volumeset
will remain 255. For one thing this is a very difficult problems to
solve in a backward compatible mannor. For another we do *NOT* want
our customers putting that much data in one volumeset anyway.

As you said you are working on splitting up you volumeset....keep
working on it. The advantages from a high availability/disaster
recovery point of view are pretty obvious (and should be persuasive
enough without me adding much).

The project to support mirroring the system volumeset is being
considered but is *NOT* committed or fully funded at this date.