HP StorageWorks Data Replication Manager HSG80 ACS Version 8.7P Configuration Guide (AA-RPHZF-TE, March 2004)

Getting Started
52 Data Replication Manager HSG80 ACS Version 8.7P Configuration Guide
Rolling Upgrade Procedure
This procedure allows you to change from SCSI-2 to SCSI-3 without stopping all I/O to the
HSG80 controllers. Use this procedure if you cannot be without constant access to your
storage. The procedure is the same as for the static upgrade above, except for the following:
1. Do not perform step 3 above to stop I/O and unmount devices.
2. Replace step 6 above with the following step 6:
6. Issue the following restart CLI command:
RESTART OTHER_CONTROLLER
LUNs assigned to the OTHER controller will fail over to THIS controller. When the
controller has fully rebooted and is back online, issue the following CLI command:
RESTART THIS_CONTROLLER
Cascaded Switches
Cascaded switches provide a DRM configuration variation that lets you:
■ Increase the distance between sites (expand the fabric)
■ Increase host or controller port connections
A cascaded switch is one where the output of one switch is connected to the input of another.
The second switch may then be connected to another switch, a host, or a controller.
Hopping
The cascading of switches employs hopping. A hop is defined as one or more connections
between two Fibre Channel switches. Two switches cascaded are equal to one hop.
Server-to-Fibre-Channel switch segments and storage-to-Fibre-Channel switch segments are
not counted as hops.
The definitive resource for SAN configuration rules is the HP StorageWorks SAN Design
Reference Guide, which is available at the following website:
http://h18006.www1.hp.com/products/storageworks/san/documentation.html
The following rules apply to hops in a DRM environment:
■ For B-series switches: Maximum of 28 switches in a fabric with no more than 7 hops
allowed from the host to either the initiator controller or the target controller.
■ For C-series switches: Maximum of 11 switches in a fabric with no more than 3 hops
allowed from a host to either the initiator or target controller.
■ For M-series switches: Maximum of 24 switches in a fabric with no more than 3 hops
allowed from a host to either the initiator or target controller.
■ Within a single fabric where switches are interconnected, each Fibre Channel switch must
have a unique domain number (Domain_ID.)
■ The maximum distance allowed using short wavelength laser GBICs and 50-micron
multimode fiber optic cable is 500 meters per cable segment.
■ The maximum distance allowed using long wavelength laser GBICs and 9-micron
single-mode fiber optic cable is 10 kilometers per cable segment.
■ Very Long Distance GBICs can extend ISLs up to 100 kilometers.
■ Wavelength Division Multiplexing (WDM) can extend up to 120 kilometers.