Dell POWEREDGE M1000E - Manual (Page 271)

Fabric OS Command Reference 243
53-1002746-01
dlsSet
2
dlsSet
Enables Dynamic Load Sharing (DLS) without frame loss.
SYNOPSIS dlsset
dlsset --enable -lossless
dlsset --disable -lossless
dlsset --help
DESCRIPTION Use this command to enable or disable Dynamic Load Sharing (DLS) in the event of a fabric change, to
configure DLS without frame loss, and to display the DLS configuration.
Dynamic load sharing optimizes the utilization of the interswitch links (ISLs) by rebalancing the paths
going over the ISLs whenever there is a fabric event that may result in a sub-optimal utilization of the ISL.
Dynamic rebalancing can be triggered by any one of the following events:
•
A change in the fabric occurs.
•
A local E_Port (including trunk ports) goes up or down.
•
A local Fx_Port goes down.
When used without operands, this command enables Dynamic Load Sharing on a switch (legacy DLS
behavior). Frames may be lost during reroute operations. If the switch has an exchanged-based routing
policy, DLS is enabled by default and this command fails with the following message: "DLS can not be
changed with current routing policy."
During the load sharing recomputation, existing routes may be moved to maintain optimal load balance.
Frame loss is unavoidable when a port goes down. To prevent frames from being lost during this
operation, you can enable DLS without frame loss by issuing this command with the --enable -lossless
option.
Dynamic load sharing without frame loss is supported in logical fabrics and is configured per logical
switch. However, there is a potential impact on other logical switches because they share the same
hardware. Chassis permissions are required to configure DLS in a logical fabric environment.
For example, assume a chassis is partitioned as follows: logical switch LS1 consists of ports 1/0-1/5, and
logical switch LS2 consists of ports 1/6-1/10. Lossless is enabled on logical switch LS1. Because the
ports 1/0-1/10 share the same chip, traffic in LS2 is affected whenever traffic for LS1 on ports 1/0-1/5 is
rebalanced. The impact on LS2 depends on the configuration on LS2:
•
If the Lossless feature is enabled on LS1, traffic pauses and resumes without frame loss on both
switches at the same time.
•
If the Lossless feature is disabled on LS1, traffic on LS2 is not affected.