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 memory that the port buffers take.

PARAMETERS

       For read-write parameters, the following describes only the write direction, i.e. as used
       with the set command. For the show command, the parameter 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 individual 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 PARAMETERS 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.kernel.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>