dcb-buffer8
Show / manipulate port buffer settings of the dcb (data center bridging) subsystem
Usage
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 | }
Overview
dcb buffer is used to configure assignment of traffic to port buffers based on traffic priority, and sizes of those buffers. It can also be 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.
Releases
3 releases since Debian 12 (Bookworm); the text changed 1 time.