[Info-vax] How do I avoid a full disk shadow copy when I shutdown/boot a node back into the cluster?

[Len Whitwer]

On Apr 4, 12:23 pm, Ken Fairfield <ken.fairfi... at gmail.com> wrote:
> On Wednesday, April 4, 2012 12:03:32 PM UTC-7, Len Whitwer wrote:
> > Hi All:
>
> > How do I avoid a full disk shadow copy when I shutdown/boot a node
> > back into the cluster?
>
> > Have two rx3600's with a SAN on each running OVMS I64 ver 8.4 with
> > clustering and Volume Shadowning.
>
> > When one node (Clustered) goes down and then comes back into the
> > cluster a
> > COMPLETE shodow copy action is initiated on there-join. This takes
> > about 9 hours
> > which is unacceptable. There has to be a way around this where only
> > the files
> > that have CHANGED get updated!!!!!
>
> 1) Be sure you've configured and enabled HBMM (Host-Based Mini-Merge)
>    on all your shadow volumes.
>
> 2) Be sure you've called the appropriate shutdown procedures for
>    your various applications in SYSHUTDWN.COM.
>
> Regarding (2), VMS will do its best to kill all processes on the
> system before dismounting the shadow volumes, but there are a
> variety of reasons it might no succeed.  It's up to the system
> manager to invoke any and all application shutdown procedures
> (think databases for example) during system shutdown.
>
> Regarding (1), the system disk is always subject to merge on
> shutdown, even a normal/controlled shutdown.  With the move to
> FibreChannel (from CI), volume merges are no longer done in the
> storage controller.  Rather, as of v7.3-2 (or late v7.3-1 with
> appropriate ECOs), HBMM uses the functionality initially developed
> for mini-copy to keep track of modified blocks (groups of 127
> blocks usually) that will need to be merged should the shadow
> volume be dismounted abnormally.  Of course for this to work,
> you need to be in a cluster and at least one cluster member
> must survive the reboot or crash of some other system.  The
> surviving member will merge the volume(s).
>
>     -Ken- Hide quoted text -
>
> - Show quoted text -

Thanks Ken. Will check out HBMM.

Len