Chapter 2. Initial configuration 31
Connect SAS port 3 of the left node canister in the control enclosure to SAS port 1 of
the left expansion canister in the second enclosure (above the control enclosure, as
shown in Figure 2-1 on page 30).
Connect SAS port 3 of the right node canister in the control enclosure to SAS port 1 of
the right expansion canister in the second enclosure (above the control enclosure, as
shown in Figure 2-1 on page 30).
Continue to add expansion controllers alternately on the two different SAS chains that
originate at ports 3 and 4 on the control enclosure node canisters. No expansion enclosure
should be connected to both SAS chains.
2.2 SAN configuration planning
The recommended SAN configuration is composed of a minimum of two fabrics that
encompass all host ports and any ports on external storage systems that are to be virtualized
by IBM Storwize V5000. The IBM Storwize V5000 ports are evenly split between the two
fabrics to provide redundancy if one of the fabrics goes offline (planned or unplanned).
Zoning must be implemented after the IBM Storwize V5000, hosts, and optional external
storage systems are connected to the SAN fabrics.
To enable the node canisters to communicate with each other in band, create a zone with only
the IBM Storwize V5000 WWPNs (two from each node canister) on each of the two fabrics. If
an external storage system is to be virtualized, create a zone in each fabric with the IBM
Storwize V5000 WWPNs (two from each node canister) with up to a maximum of eight
WWPNs from the external storage system. Assuming every host has a Fibre Channel
connection to each fabric, create a zone with the host WWPN and one WWPN from each
node canister in the IBM Storwize V5000 system in each fabric. The critical point is that there
should only ever be one initiator (host HBA) in any zone. For load balancing between the
node ports on the IBM Storwize V5000, alternate the host Fibre Channel ports between the
ports of the Storwize V5000.
There should be a maximum of eight paths through the SAN from each host to the IBM
Storwize V5000. Hosts where this number is exceeded are not supported. The restriction is
there to limit the number of paths that the multi-pathing driver must resolve. A host with only
two HBAs should not exceed this limit with proper zoning in a dual fabric SAN.
Disk drives: The disk drives that are included with the control enclosure (model 2077-12C
or 2077-24C) are part of the single SAS chain. The expansion enclosures should be
connected to the SAS chain as shown in Figure 2-1 on page 30 so that they can use the
full bandwidth of the system.
Virtualized Storage: External storage systems that are to be virtualized are used for
migration purposes only.
Maximum ports or WWPNs: IBM Storwize V5000 supports a maximum of 16 ports or
WWPNs from a virtualized external storage system.
32 Implementing the IBM Storwize V5000
Figure 2-2 shows how to cable devices to the SAN. Refer to this example as the zoning is
described.
Figure 2-2 SAN cabling and zoning diagram
Create a host/IBM Storwize V5000 zone for each server that volumes are mapped to and
from the clustered system, as shown in the following examples in Figure 2-2:
򐂰 Zone Host 1 port 1 (HBA 1) with both node canister ports 1
򐂰 Zone Host 1 port 2 (HBA 2) with both node canister ports 2
򐂰 Zone Host 2 port 1 (HBA 1) with both node canister ports 3
򐂰 Zone Host 2 port 2 (HBA 2) with both node canister ports 4
Similar zones should be created for all other hosts with volumes on the Storwize V5000.
Verify interoperability with which the IBM Storwize V5000 connects to SAN switches or
directors by following the requirements that are provided at this website:
http://www-01.ibm.com/support/docview.wss?uid=ssg1S1004111
Switches or directors are at the firmware levels that are supported by the IBM Storwize
V5000.
Important: IBM Storwize V5000 port login maximum that is listed in the restriction
document must not be exceeded. The document is available at this website:
http://www-01.ibm.com/support/docview.wss?uid=ssg1S1004233
Connectivity issues: If you have any connectivity issues between IBM Storwize V5000
ports and Brocade SAN Switches or Directors at 8 Gbps, see this website for the correct
setting of the fillword port config parameter in the Brocade operating system:
http://www-01.ibm.com/support/docview.wss?rs=591&uid=ssg1S1003699

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