DCB-BUFFER(8) Linux DCB-BUFFER(8)
NAME
dcb-buffer - show / manipulate port buffer settings of the DCB (Data
Center Bridging) subsystem
SYNOPSIS
dcb [ OPTIONS ] buffer { COMMAND | help }
dcb buffer show dev DEV [ prio-buffer ] [ buffer-size ] [ total-size ]
dcb buffer set dev DEV [ prio-buffer PRIO-MAP ] [ buffer-size SIZE-MAP ]
PRIO-MAP := [ PRIO-MAP ] PRIO-MAPPING
PRIO-MAPPING := { PRIO | all }:BUFFER
SIZE-MAP := [ SIZE-MAP ] SIZE-MAPPING
SIZE-MAPPING := { BUFFER | all }:SIZE
PRIO := { 0 .. 7 }
BUFFER := { 0 .. 7 }
SIZE := { INTEGER | INTEGERK | INTEGERM | ... }
DESCRIPTION
dcb buffer is used to configure assignment of traffic to port buffers
based on traffic priority, and sizes of those buffers. It can be also
used to inspect the current configuration, as well as total device mem-
ory that the port buffers take.
PARAMETERS
For read-write parameters, the following describes only the write direc-
tion, i.e. as used with the set command. For the show command, the para-
meter name is to be used as a simple keyword without further arguments.
This instructs the tool to show the value of a given parameter. When no
parameters are given, the tool shows the complete buffer configuration.
total-size
A read-only property that shows the total device memory taken up
by port buffers. This might be more than a simple sum of individ-
ual buffer sizes if there are any hidden or internal buffers.
prio-buffer PRIO-MAP
PRIO-MAP uses the array parameter syntax, see dcb(8) for details.
Keys are priorities, values are buffer indices. For each priority
sets a buffer where traffic with that priority is directed to.
buffer-size SIZE-MAP
SIZE-MAP uses the array parameter syntax, see dcb(8) for details.
Keys are buffer indices, values are sizes of that buffer in
bytes. The sizes can use the notation documented in section PA-
RAMETERS at tc(8). Note that the size requested by the tool can
be rounded or capped by the driver to satisfy the requirements of
the device.
EXAMPLE & USAGE
Configure the priomap in a one-to-one fashion:
# dcb buffer set dev eth0 prio-buffer 0:0 1:1 2:2 3:3 4:4 5:5 6:6 7:7
Set sizes of all buffers to 10KB, except for buffer 6, which will have
the size 1MB:
# dcb buffer set dev eth0 buffer-size all:10K 6:1M
Show what was set:
# dcb buffer show dev eth0
prio-buffer 0:0 1:1 2:2 3:3 4:4 5:5 6:6 7:7
buffer-size 0:10Kb 1:10Kb 2:10Kb 3:10Kb 4:10Kb 5:10Kb 6:1Mb 7:10Kb
total-size 1222Kb
EXIT STATUS
Exit status is 0 if command was successful or a positive integer upon
failure.
SEE ALSO
dcb(8)
REPORTING BUGS
Report any bugs to the Network Developers mailing list <netdev@vger.ker-
nel.org> where the development and maintenance is primarily done. You
do not have to be subscribed to the list to send a message there.
AUTHOR
Petr Machata <me@pmachata.org>
iproute2 12 November 2020 DCB-BUFFER(8)
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