Users Guide

buffer size. If the buffer size and DCB buffer threshold settings are applied on one or more ports, a validation is
performed to determine whether following condition is satisfied: If the shared buffer size is more than the total
PFC buffer size value, the configuration is not saved and a system logging message is generated as follows:
Shared-pfc-buffer-size <= (Total-pfc-buffer-size — Σpfc priority <> buffer-size on each port, priority).
Dell(conf)#dcb pfc-shared-buffer-size 2000
%ERROR: pfc shared buffer size configured cannot accommodate existing buffer
requirement in the system.
Enter a smaller value for the shared buffer size or increase the total buffer size appropriately by using the dcb
pfc-total- buffer-size command.
Example
Dell(conf)#dcb pfc-shared-buffer-size 5000
dcb pfc-total-buffer-size
Configure the total buffer size for PFC in kilobytes.
Syntax
dcb pfc-total—buffer—size KB
Parameters
KB Enter a number in the range of 0 to 7787.
Default The default is 6592KB.
Command Modes CONFIGURATION mode
Command History
Version Description
9.9(0.0) Introduced on the M I/O Aggregator and the FN I/O Aggregator.
Usage Information
Configure the maximum buffer available for PFC traffic. You can choose to increase or decrease the buffer size
that is allocated in the system by default. However, if you modify the PFC buffer size lower than the previously
configured size, the system determines whether this reduction in size is valid without disrupting the existing
configuration. In such a scenario, disable and re-enable DCB. For example, if you modify the total buffer size as
4000 KB from the previous size of 5000 KB, an error message is displayed that this reduction cannot be
performed owing to existing system configuration because of queues that are being currently in process.
The lossless queue limit per port is validated based on the dcb pfc-queues command. PFC queue configuration
identifies the maximum number of queues a port can support. Although the queue limit per port is a baseline when
dynamic buffering is enabled, the limit per port for queues depends on the availability of the buffer.
Example
Dell(conf)#dcb pfc-total-buffer-size 5000
Dell(conf)#dcb pfc-total-buffer-size 4000
%ERROR: Total pfc buffer size configured cannot accommodate existing buffer
requirement in the system.
dcb-buffer-threshold
Configure the profile name for the DCB buffer threshold.
Syntax
dcb buffer—threshold profile-name
Data Center Bridging (DCB) 105