I'm running Netware 6.5 SP7 Clustered on an two HP DL380 G3's using a
locally attached MSA500 G2 via a Smart Array 642 controllers. This is a
GroupWise Post Office and Domain database. This portion of the GroupWise
system is a fairly active 1000 user Post office with approximately 650
active user connections at peak.

Now for the question. What type of performance is required for the
mirroring process. If you mirror a faster drive onto a slower drive, are
you limiting overall performance to that of the slower drive, or will it
basically queue up changes until it can catch up?

I would be mirroring the GroupWise Data from the MSA500 G2 onto a Lefthand
Networks "Campus SAN" iscsi volume. The issue is that the iscsi SAN doesn't
have the performance to keep up with the GroupWise system, but it offers
excellent Fault tolerance.

The "Campus SAN", in essence uses a Network replication enabling me to lose
two of my four storage modules (ie loss of a Building), without disrupting
access to or the integrity of the data. My desired Goal is to get the
performance of the MSA500 for immediate transactions, while replicating the
data at near real time to the more fault tolerant iSCSI SAN...

Is it feasible, or would the entire process cause such a replication lag as
to reduce the performance of the entire system to that of the iSCSI
connection or worse... Or on that note, would is create a data corruption
situation if it can not process the mirroring quickly enough.

Thank You, Sorry for the long winded post.