.SAN design reference guide Vol. 1-5 785350-001

Table 135 FCIP network consideration
FactorsUse existing network?Configuration type
For peak performance, HP recommends using a
separate network. A dedicated network is the
benchmark for mirrored FCIP SAN systems.
NoMirrored FCIP SAN
Because data migration is usually a one-time event
for upgrade or maintenance purposes, you can use
YesData migration your existing network. However, network
performance can be significantly degraded during
data migration.
FCIP gateways support Ethernet connections of 10 Mb/s, 100 Mb/s, and 1 Gb/s. Select the
network connection that matches the amount of data to be transferred and the time allowed for
that transfer.
FCIP bandwidth considerations
When sites are located many miles apart, there can be unacceptable delays in the completion of
an I/O transaction. Increasing the available bandwidth may not solve this problem.
Recommendations for managing bandwidth with FCIP
In an enterprise-level SAN with multiple copy sets, merges, or full copies, normalization time can
be extensive. Use the following guidelines to decrease the normalization time in an HP P6000
Continuous Access environment with the EVA family of storage arrays:
• Set up and normalize all copy sets at the same location with direct Fibre Channel connections,
and then move the remote hardware to the remote site for normal operations. New copy sets
will then normalize at the slower link speeds.
• Increase link bandwidth while normalization is taking place.
• Determine which data must be immediately available after a disaster, and save that data to
a copy set. This applies to EVA storage arrays. Back up all other data using backup methods
that can run at off-peak times.
• Most IP networks do not manage bandwidth to each connection. As traffic increases due to
other demands on the network, you can use bandwidth from the replication application. Use
the following techniques to minimize impact on performance:
◦ Create VPNs with QoS through your local routers for the replication circuit.
◦ Create separate physical networks for EVA storage arrays.
◦ Guarantee the bandwidth using a third-party router and/or QoS vendor.
• Distance affects the amount of data that can be transmitted across a link. Consider these
site-planning best practices:
◦ Use the shortest possible distance between remote sites.
◦ Always use the least possible number of copy sets. If possible, combine virtual disks that
have the same failover requirements because it is best to have one copy set per application
instance.
◦ Copy only data that is more expensive to re-create than to copy.
◦ Add copy sets that will not impact normal data traffic.
◦ Consider adding controller pairs to use available bandwidth effectively.
For additional recommendations, see the HP P6000 Continuous Access Implementation Guide.
268 SAN extension