
28
If your system comes with a total of 8+ host ports, it is recommended that you obtain more
disk drives by attaching a JBOD so that you can create host-port corresponding 6-member
logical drives (RAID-5) or 8-member logical drives (RAID-6). These logical drives leverage
the bandwidth of each host port.
There are other considerations:
•
For example, a spare drive carries no data stripes and will not contribute to disk-level
performance. Refer to the documentation for your hard drives for performance data.
•
The disk drives in the same logical array should have the same capacity, but it is
preferred that all the drives within a chassis have the same capacity.
•
Disk drives in the same logical drive should have the same capacity, but it is
preferred that all the disk drives within a chassis have the same capacity. Tiered
storage configuration is supported. However, you should not include both SAS and
SATA drives in a logical drive.
•
A spare drive should have a minimum capacity that is equivalent to the largest drive
that it is expected to replace. If the capacity of the spare is less than the capacity of
the drive it is expected to replace, the controller will not proceed with the failed drive
rebuild.
•
When cabling, follow all the specifications. Pay attention to signal quality and avoid
electronic noise from adjacent interfaces, e.g., do not lay power cords on optical
cables.
•
When rack-mounted, leave enough slack in the cables so that they do not bend to a
diameter of less than 76mm (3 inches).
•
Route the cables away from places where it can be damaged by other devices, e.g.,
foot traffic or fan exhaust.
•
Do not over-tighten or bend the cables.
Host-Side Topologies
The primary concern for configuring host-side topologies is to avoid points of failure. It is
therefore recommended that the host ports are connected to at least two HBAs.
NOTE
In order to manage the fault-tolerant data paths and to optimize data throughput on
multiple data paths, it is necessary to apply EonPath multipath software or utilities
such as Linux Device Mapper.
Host port channel designation may vary from system to system, please refer to the
following topologies as a guide to create your own connections to suit your needs.
Host-Side Parameters
It is STRONGLY recommended that users use the default settings with their system. Should
you feel the need to adjust your host-side parameters, please consult on-site technical
personnel or seek technical support from your vendor.
Maxi
mum Concurrent Host LUN Connection (“Nexus” in SCSI)
The "Max Number of Concurrent Host-LUN Connection" menu option is used to set the
maximum number of concurrent host-LUN connections.