Emulex 355 - Manual (Page 48)

E MULEX M ODEL 355 SAN S TORAGE S WITCH
U SER ’ S G UIDE C HAPTER 3: S WITCH M ANAGEMENT
E MULEX C ORPORATION 45
P ART N UMBER 00041411-002 R EV . B
Load balancing configuration settings are available on the Web Manager’s Load Balancing page. Before
implementing load balancing on the switch, the automatic trunking settings must be configured. See
“Automatic Trunking” on page 43 for additional information.
To view the Load Balancing page:
Click Advanced Functions > Load Balancing.
The page is arranged as a grid of check boxes for assigning ports to cascades (“Trunk Groups”).
Load Indicators
The Load Balancing page incorporates two sets of visual indicators for measuring traffic:
• Port Load Indicators–the horizontal bars on the right side of the page that display the current
load for each port.
• Trunk Load Indicators–the vertical bars at the bottom of the page that display the current load for
each trunk group.
These bars indicate the amount of traffic across a trunk or port. The size of the bars increase in
correlation to the amount of traffic and, as a bar’s size increases, can identify a specific trunk or port that
is overloaded. If overloading occurs, move one or more ports to a different trunk in the group.
To change the load balancing settings:
1. Click a Trunk Group option to place a port into a specific trunk group.
2. Continue to assign ports to trunk groups as necessary.
3. When finished, click Submit.
Fairness and Prioritization
The concept of “fairness” is based on the principle of ensuring fair device access and communication
across all devices in a storage system. The switch incorporates fairness and prioritization through
InSpeed technology and Automatic Trunking and Load Balancing functionality. In cooperation with each
other, these features ensure even and equal access through multiple links fairly–effectively multiplying
bandwidth.
Device prioritization can be achieved using Load Balancing and assigning only a specific device port to
a particular cascade. This ensures that a specific device will always have a dedicated trunk.
Note: When tape drives or tape libraries are included in multiple switch configurations incorporating
multiple trunks, place the tape drive or tape library and any devices that access those devices
on the secondary (duplicate) trunk, not the primary trunk.
Figure 3-25: Load Balancing page