Users Guide

Command History
Version Description
9.9(0.0) Introduced on the M I/O Aggregator and the FN I/O Aggregator.
Usage Information Congure the maximum shared buer available for PFC trac. You can choose to increase or decrease the
shared buer that is allocated in the system by default. Congure the shared buer size less than the total
PFC buer size. If the buer size and DCB buer threshold settings are applied on one or more ports, a
validation is performed to determine whether following condition is satised: If the shared buer size is more
than the total PFC buer size value, the conguration is not saved and a system logging message is
generated as follows:
Shared-pfc-buer-size <= (Total-pfc-buer-size — Σpfc priority <> buer-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 buer size or increase the total buer size appropriately by using the
dcb pfc-total- buffer-size command.
Example
Dell(conf)#dcb pfc-shared-buffer-size 5000
dcb pfc-total-buer-size
Congure the total buer 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
Congure the maximum buer available for PFC trac. You can choose to increase or decrease the buer
size that is allocated in the system by default. However, if you modify the PFC buer size lower than the
previously congured size, the system determines whether this reduction in size is valid without disrupting
the existing conguration. In such a scenario, disable and re-enable DCB. For example, if you modify the total
buer 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 conguration 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
conguration identies the maximum number of queues a port can support. Although the queue limit per
port is a baseline when dynamic buering is enabled, the limit per port for queues depends on the availability
of the buer.
104
Data Center Bridging (DCB)