16MB in ingress across all ports per ASIC.
9MB in egress across all ports per ASIC.
The following default buffer allocations per
port exist for the
Cisco Nexus device:
Table 1. Cisco Nexus Device
Platform Default Buffer Allocations Per Port
Traffic Class
|
Ingress Buffer
(KB)
|
Class-fcoe at
300M for a 10G Port
|
161.25
|
Class-fcoe at
300M for a 40G Port
|
182.5
|
Class-fcoe at
3000M for a 10G Port
|
412.5
|
Class-fcoe at
3000M for a 40G Port
|
1300
|
User-defined
no-drop at 300M for a 10G Port
|
160
|
User-defined
no-drop at 300M for a 40G Port
|
181.25
|
User-defined
no-drop at 3000M for a 10G Port
|
411.875
|
User-defined
no-drop at 3000M for a 40G Port
|
1298.125
|
The default buffer
allocation varies depending on the type of class. For example, if you create a
regular tail drop traffic class the default allocation is 22.7KB, unless you
specify a larger size using the
queue-limit
command.
To increase the
ingress buffer space available to a user-created qos-group, from a network-qos
policy-map, use the
queue-limit
command.
In addition to ingress
buffer allocated for each user-created qos-group there is an additional 29.76KB
buffer required at egress for each qos-group.
With the default QoS
configuration, all of the available buffer (470KB) is allocated to the
class-default. When you create a new qos-group, the buffer required for the new
qos-group will be taken away from class-default. The amount of buffer that is
left for class-default equals 470 minus the ingress buffer used by other
qos-groups minus 29.76KB and times the number of qos-groups.
Note |
Each new class
requires an additional 29.76KB, so the exact amount of buffer that is left in
the class default equals 470 minus the buffer used by other qos-groups minus
29.76KB times the number of qos-groups.
|
The default QoS policy
for the
Cisco Nexus device
does not create class-fcoe and does not reserve buffer and qos-group for FCoE
traffic.
The
show queuing
interface command can display the amount of ingress buffer
allocated for each qos-group