08-Data Buffer Configuration Commands
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Table of Contents
1 Data Buffer Configuration Commands
Automatic Data Buffer Configuration Commands
Manual Data Buffer Configuration Commands
buffer egress queue guaranteed
Syntax
burst-mode enable
undo burst-mode enable
View
System view
Default Level
2: System level
Parameters
None
Description
Use the burst-mode enable command to enable the burst function.
Use the undo burst-mode enable command to disable the burst function.
By default, the burst function is disabled.
The burst function allows the switch to automatically determine the shared resource size, the minimum guaranteed resource size for each queue, the maximum shared resource size for each queue, and the maximum shared resource size per port. The function optimizes the packet buffering scheme to enhance forwarding performance.
The burst-mode enable command cannot work in conjunction with any manual data buffer configuration commands.
Examples
# Enable the burst function.
<Sysname> system-view
[Sysname] burst-mode enable
l The data buffer configuration is complicated and significantly impacts the forwarding performance of a device. You should not modify the data buffer parameters unless you are sure that your device will benefit from the change. If a larger buffer is needed, it is recommended that you enable the burst function to automatically allocate buffer.
l The commands in this section are mutually exclusive with the burst-mode enable command.
Syntax
buffer apply
undo buffer apply
View
System view
Default Level
2: System level
Parameters
None
Description
Use the buffer apply command to apply the configured data buffer settings.
Use the undo buffer apply command to restore the default.
Table 1-1 shows the default data buffer allocation schemes of the S5820X and the S5800 series switches.
Table 1-1 Default data buffer allocation schemes of the S5820X and the S5800 series switches
|
Hardware platform |
Resource type |
Shared resource size |
Minimum guaranteed resource size per queue |
Maximum shared resource size per queue |
Maximum shared resource size per port |
|
S5800 series switches |
Cell resource |
69% |
12% |
6% |
33% |
|
Packet resource |
70% |
12% |
6% |
33% |
|
|
S5820X series switches |
Cell resource |
62% |
12% |
6% |
33% |
The S5820X series switches do not support the packet resource.
Examples
# Apply the data buffer settings.
<Sysname> system-view
[Sysname] buffer apply
Syntax
buffer egress [ slot slot-number ] { cell | packet } queue queue-id guaranteed ratio ratio
undo buffer egress [ slot slot-number ] { cell | packet } queue queue-id guaranteed
View
System view
Default Level
2: System level
Parameters
slot slot-number: Specifies an IRF member device number. For a standalone device, the slot-number argument can only be 1. In an IRF virtual device, with slot-number specified, this command configures the buffer resource of the member device specified by slot-number; without slot-number specified, this command configures the buffer resource of the master device in the IRF virtual device.
cell: Configures the minimum guaranteed resource size for a queue in the cell resource.
packet: Configures the minimum guaranteed resource size for a queue in the packet resource. This keyword is not available on an S5820X series switch.
queue-id: Specifies the ID of the queue to be configured, in the range of 0 to 7.
ratio: Sets the minimum guaranteed resource size for the specified queue as a percentage of the dedicated buffer per port in the range of 0 to 100.
Description
Use the buffer egress queue guaranteed command to configure the minimum guaranteed resource size for a queue in the cell resource or packet resource.
Use the undo buffer egress queue guaranteed command to restore the default.
By default, the minimum guaranteed resource size for a queue is 12% of the dedicated buffer of the port in both the cell resource and the packet resource.
The minimum guaranteed resource settings of a queue take effect globally, and apply to the queue with the same number on each port.
As the dedicated resource of a port is shared by eight queues, modifying the minimum guaranteed resource size for a queue can affect the other queues. The system automatically allocates the remaining dedicated resource among all queues that have not been manually assigned a minimum guaranteed resource space. For example, if you set the minimum guaranteed resource size to 30% for a queue, the other seven queues will each share 10% of the remaining dedicated resource of the port.
Examples
# Configure 20% of the dedicated buffer per port as the minimum guaranteed resource for queue 0 in the cell resource.
<Sysname> system-view
[Sysname] buffer egress cell queue 0 guaranteed ratio 20
# In an IRF virtual device, configure 15% of the dedicated buffer per port as the minimum guaranteed resource for queue 0 in the cell resource on member device 2.
<Sysname> system-view
[Sysname] buffer egress slot 2 cell queue 0 guaranteed ratio 15
Syntax
buffer egress [ slot slot-number ] { cell | packet } queue queue-id shared ratio ratio
undo buffer egress [ slot slot-number ] { cell | packet } queue queue-id shared
View
System view
Default Level
2: System level
Parameters
slot slot-number: Specifies an IRF member device number. For a standalone device, the slot-number argument can only be 1. In an IRF virtual device, with slot-number specified, this command configures the buffer resource of the member device specified by slot-number; without slot-number specified, this command configures the buffer resource of the master device in the IRF virtual device.
cell: Configures the maximum shared resource size for a queue in the cell resource.
packet: Configures the maximum shared resource size for a queue in the packet resource. This keyword is not available on an S5820X series switch.
queue-id: Specifies the ID of the queue to be configured, in the range of 0 to 7.
ratio: Sets the maximum shared resource size for the specified queue as a percentage of the shared resource in the range of 0 to 100.
Description
Use the buffer egress queue shared command to configure the maximum shared resource size for a queue in the cell resource or packet resource.
Use the undo buffer egress queue shared command to restore the default.
By default, the maximum shared resource size for a queue is 6% of the shared resource in both the cell resource and the packet resource.
The maximum shared resource settings of a queue take effect globally, and apply to the queue with the same number on each port.
Examples
# Set the maximum shared resource size for queue 0 to 10% in the cell resource.
<Sysname> system-view
[Sysname] buffer egress cell queue 0 shared ratio 10
# In an IRF virtual device, set the maximum shared resource size of queue 0 to 5% in the cell resource on member device 2.
<Sysname> system-view
[Sysname] buffer egress slot 2 cell queue 0 shared ratio 5
Syntax
buffer egress [ slot slot-number ] { cell | packet } shared ratio ratio
undo buffer egress [ slot slot-number ] { cell | packet } shared
View
System view
Default Level
2: System level
Parameters
slot slot-number: Specifies an IRF member device number. For a standalone device, the slot-number argument can only be 1. In an IRF virtual device, with slot-number specified, this command configures the buffer resource of the member device specified by slot-number; without slot-number specified, this command configures the buffer resource of the master device in the IRF virtual device.
cell: Configures the maximum shared resource size per port in the cell resource.
packet: Configures the maximum shared resource size per port in the packet resource. This keyword is not available on an S5820X switch.
ratio: Sets the maximum shared resource size per port as a percentage of the shared resource in the range of 0 to 100.
Description
Use the buffer egress shared command to configure the maximum shared resource size per port in the cell resource or packet resource.
Use the undo buffer egress shared command to restore the default.
By default, the maximum shared resource size per port is 33% of the shared resource in both the cell resource and the packet resource.
Examples
# Set the maximum shared resource size per port to 30% in the cell resource.
<Sysname> system-view
[Sysname] buffer egress cell shared ratio 30
# In an IRF virtual device, set the maximum shared resource size per port to 40% in the cell resource on member device 2.
<Sysname> system-view
[Sysname] buffer egress slot 2 cell shared ratio 40
Syntax
buffer egress [ slot slot-number ] { cell | packet } total-shared ratio ratio
undo buffer egress [ slot slot-number ] { cell | packet } total-shared
View
System view
Default Level
2: System level
Parameters
slot slot-number: Specifies an IRF member device number. For a standalone device, the slot-number argument can only be 1. In an IRF virtual device, with slot-number specified, this command configures the buffer resource of the member device specified by slot-number; without slot-number specified, this command configures the buffer resource of the master device in the IRF virtual device.
cell: Configures the shared resource size in the cell buffer.
packet: Configures the shared resource size in the cell buffer. This keyword is not available on an S5820X series switch.
ratio: Sets the shared resource size as a percentage of the cell resource or packet resource in the range of 0 to 100.
Description
Use the buffer egress total-shared command to configure the shared resource size in the cell resource or packet resource.
Use the undo buffer egress total-shared command to restore the default.
By default, on an S5800 series switch, 69% of the cell resource is the shared resource and 70% of the packet resource is the shared resource; on an S5820X series switch, 62% of the cell resource is the shared resource.
Examples
# Set 50% of the cell resource as the shared resource.
<Sysname> system-view
[Sysname] buffer egress cell total-shared ratio 50
# In an IRF virtual device, set 65% of the cell resource as the shared resource on member device 2.
<Sysname> system-view
[Sysname] buffer egress slot 2 cell total-shared ratio 65
