Networking

Edit online

The FileNet® P8 servers under z/VM® communicate over a virtual guest-to-guest network using a z/VM Virtual Switch (VSWITCH).

The virtual network device appears as 'GuestLAN QDIO' type in Linux™ when listing the devices with the lsqeth command.

Sample command: lsqeth for the virtual network device

# lsqeth eth1 
Device name                  : eth1 
--------------------------------------------- 
        card_type            : GuestLAN QDIO 
        cdev0                : 0.0.1000 
        cdev1                : 0.0.1001 
        cdev2                : 0.0.1002 
        chpid                : 02 
        online               : 1 
        portname             : osaport 
        portno               : 0 
        route4               : no 
        route6               : no 
        checksumming         : sw checksumming 
        state                : UP (LAN ONLINE) 
        priority_queueing    : always queue 2 
        fake_broadcast       : 0 
        buffer_count         : 128 
        layer2               : 0 
        large_send           : no 
        isolation            : none 
        sniffer              : 0

The buffer count for the network devices was increased for all FileNet servers:

Increased the number of buffers for inbound traffic to 128 (default is 64) at
```
/etc/udev/rules.d/51-qeth-0.0.1000.rules
```
where 1000 is first cdev of the virtual network device in this case

The following line was added to the udev rule definition to enhance the buffer count:

ACTION==“add”, SUBSYSTEM==“ccwgroup”, KERNEL==“0.0.1000”, ATTR{buffer_count}=“128”

See also Linux on System z®, Tuning hints and tips:

https://www.ibm.com/docs/en/linux-on-systems?topic=2018-tuning-hints-tips