Reference Guide

298 | Z-Series Debugging and Diagnostics
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Buffer tuning commands
Configuration changes take effect immediately and appear in the running configuration. Since under
normal conditions all ports do not require the maximum possible allocation, the configured dynamic
allocations can exceed the actual amount of available memory; this is called oversubscription. If you
choose to oversubscribe the dynamic allocation, a burst of traffic on one interface might prevent other
interfaces from receiving the configured dynamic allocation, which causes packet loss.
You cannot allocate more than the available memory for the dedicated buffers. If the system determines
that the sum of the configured dedicated buffers allocated to the queues is more than the total available
memory, the configuration is rejected, returning a syslog message similar to the following.
Note: Buffer profile queue 1 is not supported. Use default buffer profile queue 4.
Task Command Command Mode
Define a buffer profile for the FP queues.
buffer-profile fp fsqueue
CONFIGURATION
Define a buffer profile for the CSF queues.
buffer-profile csf csqueue
CONFIGURATION
Change the dedicated buffers on a physical 1G
interface.
buffer dedicated
BUFFER PROFILE
Change the maximum amount of dynamic buffers
an interface can request.
buffer dynamic
BUFFER PROFILE
Change the number of packet-pointers per queue.
buffer packet-pointers
BUFFER PROFILE
Apply the buffer profile to a line card.
buffer fp-uplink linecard
CONFIGURATION
Apply the buffer profile to a CSF to FP link.
buffer csf linecard
CONFIGURATION
FTOS Behavior: If you attempt to apply a buffer profile to a non-existent port-pipe, FTOS displays the following
message. However, the configuration still appears in the running-config.
%DIFFSERV-2-DSA_BUFF_CARVING_INVALID_PORT_SET: Invalid FP port-set 2 for linecard 2. Valid range of
port-set is <0-1>
Table 12-6. Buffer Allocation Error
00:04:20: %S50N:0 %DIFFSERV-2-DSA_DEVICE_BUFFER_UNAVAILABLE: Unable to allocate dedicated buffers for
stack-unit 0, port pipe 0, egress port 25 due to unavailability of cells
FTOS Behavior: When you remove a buffer-profile using the command no buffer-profile [fp | csf] from
CONFIGURATION mode, the buffer-profile name still appears in the output of show buffer-profile [detail | summary].
After a line card reset, the buffer profile correctly returns to the default values, but the profile name remains.
Remove it from the show buffer-profile [detail | summary] command output by entering no buffer [fp-uplink |csf] linecard
port-set buffer-policy
from CONFIGURATION mode and no buffer-policy from INTERFACE mode.