IBM 2145-4F2, Installation Manual

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The SAN Volume Controller provides continuous operations and can also optimize
the data path to ensure that performance levels are maintained.
Field replaceable units (FRU) can be removed and replaced on one node while the
other node of the pair continues to run. This allows the attached hosts to continue
to access the attached storage while a node is repaired.
Related reference
“SAN Volume Controller 2145-8F2 hardware” on page 18
You need to be aware of the SAN Volume Controller 2145-8F2 hardware.
“SAN Volume Controller 2145-8F2 connectors” on page 20
The external connectors for the SAN Volume Controller 2145-8F2 can be easily
located.
SAN fabric overview
The SAN fabric is an area of the network that contains routers, gateways, hubs,
and switches. A single cluster SAN contains two distinct types of zones: a host
zone and a disk zone.
In the host zone, the host systems can identify and address the SAN Volume
Controller nodes. You can have more than one host zone. Generally, you create one
host zone for each host type. In the disk zone, the SAN Volume Controller nodes
identify the disk drives. Host systems cannot operate on the disk drives directly;
all data transfer occurs through the SAN Volume Controller nodes. Figure 9 shows
several host systems that are connected in a SAN fabric.
A cluster of SAN Volume Controller nodes is connected to the same fabric and
presents virtual disks (VDisks) to the host systems. You create these VDisks from
Fibre Channel
Fabric
Host Host Host Host
.
.
.
RAID RAID RAID RAID
. . .
Host zone
Disk zone
Node 1
Node 2
Node 3
Figure 9. Example of a SAN Volume Controller in a fabric
Chapter 1. SAN Volume Controller overview
3