Chapter 17. Configuring a Linux instance on 64-bit IBM Z

Procedure

1. Use the cio_ignore utility to remove the DASD from the list of ignored devices and make it visible to Linux:

   # cio_ignore -r device_number

   Copy to Clipboard Toggle word wrap

   Replace device_number with the device number of the DASD. For example:

   # cio_ignore -r 4b2e

   Copy to Clipboard Toggle word wrap

2. Set the device online. Use a command of the following form:

   # chccwdev -e device_number

   Copy to Clipboard Toggle word wrap

   Replace device_number with the device number of the DASD. For example:

   # chccwdev -e 4b2e

   Copy to Clipboard Toggle word wrap

1. Remove the DASD from the list of ignored devices and make it visible using the cio_ignore utility:

   # cio_ignore -r device_number

   Copy to Clipboard Toggle word wrap

   where device_number is the DASD device number.

   For example, if the device number is 021a, run:

   # cio_ignore -r 021a

   Copy to Clipboard Toggle word wrap

2. Activate the DASD by writing to the device’s uevent attribute:

   # echo add > /sys/bus/ccw/devices/dasd-bus-ID/uevent

   Copy to Clipboard Toggle word wrap

   where dasd-bus-ID is the DASD’s bus ID.

   For example, if the bus ID is 0.0.021a, run:

   # echo add > /sys/bus/ccw/devices/0.0.021a/uevent

   Copy to Clipboard Toggle word wrap

1. Use the cio_ignore utility to remove the FCP adapter from the list of ignored devices and make it visible to Linux:

   # cio_ignore -r device_number

   Copy to Clipboard Toggle word wrap

   Replace device_number with the device number of the FCP adapter. For example:

   # cio_ignore -r fcfc

   Copy to Clipboard Toggle word wrap

2. To trigger the uevent that activates the change, issue:

   # echo add > /sys/bus/ccw/devices/device-bus-ID/uevent

   Copy to Clipboard Toggle word wrap

   For example:

   # echo add > /sys/bus/ccw/devices/0.0.fcfc/uevent

   Copy to Clipboard Toggle word wrap

Procedure

1. Determine whether the qeth device driver modules are loaded. The following example shows loaded qeth modules:

   # lsmod | grep qeth
   qeth_l3                69632  0
   qeth_l2                49152  1
   qeth                  131072  2 qeth_l3,qeth_l2
   qdio                   65536  3 qeth,qeth_l3,qeth_l2
   ccwgroup               20480  1 qeth

   Copy to Clipboard Toggle word wrap

   If the output of the lsmod command shows that the qeth modules are not loaded, run the modprobe command to load them:

   # modprobe qeth

   Copy to Clipboard Toggle word wrap

2. Use the cio_ignore utility to remove the network channels from the list of ignored devices and make them visible to Linux:

   # cio_ignore -r read_device_bus_id,write_device_bus_id,data_device_bus_id

   Copy to Clipboard Toggle word wrap

   Replace read_device_bus_id,write_device_bus_id,data_device_bus_id with the three device bus IDs representing a network device. For example, if the read_device_bus_id is 0.0.f500, the write_device_bus_id is 0.0.f501, and the data_device_bus_id is 0.0.f502:

   # cio_ignore -r 0.0.f500,0.0.f501,0.0.f502

   Copy to Clipboard Toggle word wrap

3. Use the znetconf utility to sense and list candidate configurations for network devices:

   # znetconf -u
   Scanning for network devices...
   Device IDs                 Type    Card Type      CHPID Drv.
   ------------------------------------------------------------
   0.0.f500,0.0.f501,0.0.f502 1731/01 OSA (QDIO)        00 qeth
   0.0.f503,0.0.f504,0.0.f505 1731/01 OSA (QDIO)        01 qeth
   0.0.0400,0.0.0401,0.0.0402 1731/05 HiperSockets      02 qeth

   Copy to Clipboard Toggle word wrap

4. Select the configuration you want to work with and use znetconf to apply the configuration and to bring the configured group device online as network device.

   # znetconf -a f500
   Scanning for network devices...
   Successfully configured device 0.0.f500 (encf500)

   Copy to Clipboard Toggle word wrap

5. Optional: You can also pass arguments that are configured on the group device before it is set online:

   # znetconf -a f500 -o portname=myname
   Scanning for network devices...
   Successfully configured device 0.0.f500 (encf500)

   Copy to Clipboard Toggle word wrap

   Now you can continue to configure the encf500 network interface.

1. Create a qeth group device:

   # echo read_device_bus_id,write_device_bus_id,data_device_bus_id > /sys/bus/ccwgroup/drivers/qeth/group

   Copy to Clipboard Toggle word wrap

   For example:

   # echo 0.0.f500,0.0.f501,0.0.f502 > /sys/bus/ccwgroup/drivers/qeth/group

   Copy to Clipboard Toggle word wrap

2. Next, verify that the qeth group device was created properly by looking for the read channel:

   # ls /sys/bus/ccwgroup/drivers/qeth/0.0.f500

   Copy to Clipboard Toggle word wrap

   You can optionally set additional parameters and features, depending on the way you are setting up your system and the features you require, such as:

   • portno
   • layer2
   • portname

3. Bring the device online by writing 1 to the online sysfs attribute:

   # echo 1 > /sys/bus/ccwgroup/drivers/qeth/0.0.f500/online

   Copy to Clipboard Toggle word wrap

4. Then verify the state of the device:

   # cat /sys/bus/ccwgroup/drivers/qeth/0.0.f500/online
   											1

   Copy to Clipboard Toggle word wrap

   A return value of 1 indicates that the device is online, while a return value 0 indicates that the device is offline.

5. Find the interface name that was assigned to the device:

   # cat /sys/bus/ccwgroup/drivers/qeth/0.0.f500/if_name
   encf500

   Copy to Clipboard Toggle word wrap

   Now you can continue to configure the encf500 network interface.

   The following command from the s390utils package shows the most important settings of your qeth device:

   # lsqeth encf500
   Device name                     : encf500
   -------------------------------------------------
   card_type               : OSD_1000
   cdev0                   : 0.0.f500
   cdev1                   : 0.0.f501
   cdev2                   : 0.0.f502
   chpid                   : 76
   online                  : 1
   portname                : OSAPORT
   portno                  : 0
   state                   : UP (LAN ONLINE)
   priority_queueing       : always queue 0
   buffer_count            : 16
   layer2                  : 1
   isolation               : none

   Copy to Clipboard Toggle word wrap

1. Modify the DEVICE statement to reflect the contents of the if_name file from your ccw group.
2. Modify the IPADDR statement to reflect the IP address of your new interface.
3. Modify the NETMASK statement as needed.
4. If the new interface is to be activated at boot time, then make sure ONBOOT is set to yes.
5. Make sure the SUBCHANNELS statement matches the hardware addresses for your qeth device.
6. Modify the PORTNAME statement or leave it out if it is not necessary in your environment.

7. You can add any valid sysfs attribute and its value to the OPTIONS parameter. The Red Hat Enterprise Linux installation program currently uses this to configure the layer mode (layer2) and the relative port number (portno) of qeth devices.

   The qeth device driver default for OSA devices is now layer 2 mode. To continue using old ifcfg definitions that rely on the previous default of layer 3 mode, add layer2=0 to the OPTIONS parameter.

1. Use the cio_ignore utility to remove the network channels from the list of ignored devices and make them visible to Linux:

   # cio_ignore -r read_device_bus_id,write_device_bus_id,data_device_bus_id

   Copy to Clipboard Toggle word wrap

   Replace read_device_bus_id,write_device_bus_id,data_device_bus_id with the three device bus IDs representing a network device. For example, if the read_device_bus_id is 0.0.0600, the write_device_bus_id is 0.0.0601, and the data_device_bus_id is 0.0.0602:

   #  cio_ignore -r 0.0.0600,0.0.0601,0.0.0602

   Copy to Clipboard Toggle word wrap

2. To trigger the uevent that activates the change, issue:

   # echo add > /sys/bus/ccw/devices/read-channel/uevent

   Copy to Clipboard Toggle word wrap

   For example:

   # echo add > /sys/bus/ccw/devices/0.0.0600/uevent

   Copy to Clipboard Toggle word wrap

3. Check the status of the network device:

   # lsqeth

   Copy to Clipboard Toggle word wrap

4. Now start the new interface:

   # ifup enc600

   Copy to Clipboard Toggle word wrap

5. Check the status of the interface:

   # ip addr show enc600
   3: enc600:  <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
   link/ether 3c:97:0e:51:38:17 brd ff:ff:ff:ff:ff:ff
   inet 10.85.1.245/24 brd 10.34.3.255 scope global dynamic enc600
   valid_lft 81487sec preferred_lft 81487sec
   inet6 1574:12:5:1185:3e97:eff:fe51:3817/64 scope global noprefixroute dynamic
   valid_lft 2591994sec preferred_lft 604794sec
   inet6 fe45::a455:eff:d078:3847/64 scope link
   valid_lft forever preferred_lft forever

   Copy to Clipboard Toggle word wrap

6. Check the routing for the new interface:

   # ip route
   default via 10.85.1.245 dev enc600  proto static  metric 1024
   12.34.4.95/24 dev enp0s25  proto kernel  scope link  src 12.34.4.201
   12.38.4.128 via 12.38.19.254 dev enp0s25  proto dhcp  metric 1
   192.168.122.0/24 dev virbr0  proto kernel  scope link  src 192.168.122.1

   Copy to Clipboard Toggle word wrap

7. Verify your changes by using the ping utility to ping the gateway or another host on the subnet of the new device:

   # ping -c 1 192.168.70.8
   PING 192.168.70.8 (192.168.70.8) 56(84) bytes of data.
   64 bytes from 192.168.70.8: icmp_seq=0 ttl=63 time=8.07 ms

   Copy to Clipboard Toggle word wrap
8. If the default route information has changed, you must also update /etc/sysconfig/network accordingly.