Hitachi G1500 - Separation of Drive-Only Racks

When a customer adopts diverse routing of host cables within their data center for
r
esiliency and r
edundancy r
easons, it is possible to follo
w the same approach for the
dierent cables used to separate the two controller racks. Where redundant routing is
required, all of the CL1 interconnect cables along with one of the Modcon interconnect
cables should be laid through one cable route and all of the CL2 interconnect cables,
including the other Modcon cable, should be directed through an alternate cable route.
The single LAN cable can be laid through either route direction. The only supported
extended cable options are those specied by Hitachi. The intermixing of 30 meter and
100 meter cables in a single conguration is not permitted. Choosing the proper
interconnection kit or cable length is determined by the longest cable route. When using
extended cables between controllers, Hitachi recommends taking precautionary steps
such as routing the cables through the cable trays in order to protect the cables from any
accidental physical damage.
Separation of drive-only racks
A system can also be designed to separate a rack that includes a combination of
controllers and drive chassis from multiple racks containing only drive chassis.
The following gure shows a single-controller conguration with extended cabling
between rack R0 (containing the primary controller and two drive chassis) and R1 rack
(containing two drive chassis). In addition, the extended cabling between drive chassis-
only R1 rack and R2 rack. Extending the cabling between racks in a Twin Conguration is
also supported.
To avoid I/O latency issues, the sum of the length of all cables (controller-to-drive chassis
cable and drive chassis-to-drive chassis cables) cannot exceed 125 meters.
The following example shows a conguration of a controller controlling a maximum of
six drive chassis.
Figure 35 Example of a separation of drive-only racks
Extended cable connections
Chapter 5: Cable connection guidelines
Hitachi Virtual Storage Platform G1000, G1500, and VSP F1500 Hardware Guide 115