Fujitsu SPARC ENTERPRISE T5120 User Manual download pdf (Page 23)

Important Information About the SPARC Enterprise T5120 and T5220 Servers 13

Panic in nxge_start When dupb Fails (CR 6567838)

If jumbo frames are enabled, it is theoretically possible for the system to panic as a

result of a NULL pointer reference. This scenario is only possible with frame size

larger than 4076. Extensive testing of jumbo frames with MTU=9194 did not result in

a system panic.

Workaround: Because disabling jumbo frames or using jumbo frames with a smaller

MTU impacts system performance, apply the following workarounds only if the

system does panic.

The first workaround is to disable jumbo frames.

Open the following file:

Ensure that any line with accept_jumbo=1; is commented out. Also ensure that

there is no set nxge:nxge_jumbo_enable=1 in the /etc/system file.

If jumbo frames are enabled, then the workaround is to set MTU to a value equal or

smaller than 4076. Using port1 as an example:

1. Create a /etc/hosts file and add the following line in it:

Here nxge-port1 is the name you give to the interface. 99.99.9.1 is the IP

address you want to assign to the interface.

2. Create a /etc/hostname.nxge1 file and place the following two lines in it:

The MTU set as above will remain even after reboot. Command ifconfig nxgeX

mtu 4076 (where X is the instance number) can also be used to set MTU, but the

value will change back to the default one after reboot.

RX Jumbo Frame Throughput of nxge Drops to 30 Mbps Due

to Packet Dropping (CR 6554478)

Receive-side performance of the nxge driver drops significantly if the following two

conditions are true:

/platform/sun4v/kernel/drv/nxge.conf

99.99.9.1 nxge-port1

nxge-port1

nxge-port1 mtu 4076

1 2 ... 18 19 20 21 22 23 24 25 26 27 28 ... 57 58

No comments

Fujitsu SPARC ENTERPRISE T5120 User Manual Page 23