Dell POWEREDGE M1000E - Manual (Page 127)

Fabric OS Administrator’s Guide 127
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Lossless Dynamic Load Sharing on ports
4
ICL limitations
If ICL ports are connected during a core blade removal, it is equivalent to removing external E_Ports
which may cause I/O disruption on the ICL ports that have been removed.
If ICL ports are connected during a core blade insertion, it is equivalent to adding external E_Ports
which may cause I/O disruption due to reroutes. Lossless DLS, if enabled, takes effect to prevent
I/O disruption.
Traffic flow limitations
FA4-18 AP blades, which are supported on the Brocade DCX and DCX-4S devices, may continue to
experience frame drops after core blade removal or insertion. The path between an FA4-18 blade
and an FX8-24 blade, or vice versa, experiences I/O disruption because the FA4-18 blades do not
support this feature.
Configuring Lossless Dynamic Load Sharing
You configure Lossless DLS switch- or chassis-wide by using the dlsSet command to specify that no
frames are dropped while rebalancing or rerouting traffic.
Use the following procedure to configure Lossless Dynamic Load Sharing:
1. Connect to the switch and log in using an account with admin permissions.
2. Enter the appropriate dlsSet command to enable or disable Lossless Dynamic Load Sharing.
switch:admin> dlsset --enable -lossLess
switch:admin> dlsset --disable -lossLess
Lossless Dynamic Load Sharing in Virtual Fabrics
Enabling Lossless Dynamic Load Sharing is optional on logical switches in Virtual Fabrics. If you
enable this feature, it must be on a per-logical switch basis and can affect other logical switches in
the fabric. XISL use must be disabled for Lossless DLS to be enabled.
How DLS affects other logical switches in the fabric
On a Brocade DCX platform, logical switch 1 consists of ports 0 through 5 in slot 1. Logical switch 2
consists of ports 6 through 10 in slot 1. The Lossless DLS feature is enabled on logical switch 1.
Because ports 0 through 10 in slot 1 belong to a logical switch where Lossless DLS is enabled, the
traffic in logical switch 2 is affected whenever traffic for logical switch 1 is rebalanced.
ATTENTION
Although Lossless DSL is enabled for a specific logical switch, you must have chassis-level
permissions to use this feature.
This effect on logical switch 2 is based on the configuration on logical switch 2:
• If logical switch 2 has IOD enabled (iodSet only), IOD is enforced.
• If logical switch 2 has Lossless DLS enabled, traffic is paused and resumed.
• If logical switch 2 has no IOD (iodReset), traffic is paused and resumed.