Filter
Top Products
3 – Planning
Multiple Chassis Fabrics
59265-02 A 3-7
A
Optimizing Device Performance
When choosing a topology for a multiple chassis fabric, you should also consider
the locality of your server and storage devices and the performance requirements
of your application. Storage applications such as video distribution, medical record
storage/retrieval or real-time data acquisition can have specific latency or
bandwidth requirements.
The SANbox 5800V Series switch provides the lowest latency of any product in its
class. Refer to “Performance” on page 3-3 for information about latency. However,
the highest performance is achieved on Fibre Channel switches by keeping traffic
within a single switch instead of relying on ISLs. Therefore, for optimal device
performance, place devices on the same switch under the following conditions:
Heavy I/O traffic between specific server and storage devices.
Distinct speed mismatch between devices such as the following:
An 8-Gbps server and a slower 4-Gbps storage device
A high performance server and slow tape storage device
Domain ID, Principal Priority, and Domain ID Lock
The following switch configuration settings affect multiple chassis fabrics:
Domain ID
Principal priority
Domain ID lock
The domain ID is a unique number from 1–239 that identifies each switch in a
fabric. The principal priority is a number (1–255) that determines the principal
switch which manages domain ID assignments for the fabric. The switch with the
highest principal priority (1 is high, 255 is low) becomes the principal switch. If the
principal priority is the same for all switches in a fabric, the switch with the lowest
WWN becomes the principal switch.
The domain ID lock allows (False) or prevents (True) the reassignment of the
domain ID on that switch. Switches come from the factory with the domain ID set
to 1, the domain ID lock set to False, and the principal priority set to 254. Refer to
the Set Config Switch command in the SANbox 5800V Series Fibre Channel
Switch Command Line Interface Guide for information about changing the default
domain ID, domain ID lock, and principal priority parameters.
If you connect a new switch to an existing fabric with its domain ID unlocked, and
a domain ID conflict occurs, the new switch will isolate as a separate fabric.
However, you can remedy this by resetting the new switch or taking it offline then
putting it back online. The principal switch will reassign the domain ID and the
switch will join the fabric.