Chapter 21. Configuring a Linux instance on 64-bit IBM Z
This section describes most of the common tasks for installing Red Hat Enterprise Linux on 64-bit IBM Z.
21.1. Adding DASDs
Direct Access Storage Devices (DASDs) are a type of storage commonly used with 64-bit IBM Z. For more information, see Working with DASDs in the IBM Knowledge Center. The following example is how to set a DASD online, format it, and make the change persistent.
Verify that the device is attached or linked to the Linux system if running under z/VM.
CP ATTACH EB1C TO *
To link a mini disk to which you have access, run the following commands:
CP LINK RHEL7X 4B2E 4B2E MR
DASD 4B2E LINKED R/W
21.2. Dynamically setting DASDs online
This section contains information about setting a DASD online.
Procedure
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
Replace device_number with the device number of the DASD. For example:
# cio_ignore -r 4b2e
Set the device online. Use a command of the following form:
# chccwdev -e device_number
Replace device_number with the device number of the DASD. For example:
# chccwdev -e 4b2e
As an alternative, you can set the device online using sysfs attributes:
Use the
cd
command to change to the /sys/ directory that represents that volume:#
cd /sys/bus/ccw/drivers/dasd-eckd/0.0.4b2e/#
ls -l total 0 -r--r--r-- 1 root root 4096 Aug 25 17:04 availability -rw-r--r-- 1 root root 4096 Aug 25 17:04 cmb_enable -r--r--r-- 1 root root 4096 Aug 25 17:04 cutype -rw-r--r-- 1 root root 4096 Aug 25 17:04 detach_state -r--r--r-- 1 root root 4096 Aug 25 17:04 devtype -r--r--r-- 1 root root 4096 Aug 25 17:04 discipline -rw-r--r-- 1 root root 4096 Aug 25 17:04 online -rw-r--r-- 1 root root 4096 Aug 25 17:04 readonly -rw-r--r-- 1 root root 4096 Aug 25 17:04 use_diagCheck to see if the device is already online:
#
cat online 0If it is not online, enter the following command to bring it online:
#
echo 1 > online#
cat online 1
Verify which block devnode it is being accessed as:
#
ls -l total 0 -r--r--r-- 1 root root 4096 Aug 25 17:04 availability lrwxrwxrwx 1 root root 0 Aug 25 17:07 block -> ../../../../block/dasdb -rw-r--r-- 1 root root 4096 Aug 25 17:04 cmb_enable -r--r--r-- 1 root root 4096 Aug 25 17:04 cutype -rw-r--r-- 1 root root 4096 Aug 25 17:04 detach_state -r--r--r-- 1 root root 4096 Aug 25 17:04 devtype -r--r--r-- 1 root root 4096 Aug 25 17:04 discipline -rw-r--r-- 1 root root 0 Aug 25 17:04 online -rw-r--r-- 1 root root 4096 Aug 25 17:04 readonly -rw-r--r-- 1 root root 4096 Aug 25 17:04 use_diagAs shown in this example, device 4B2E is being accessed as /dev/dasdb.
These instructions set a DASD online for the current session, but this is not persistent across reboots.
For instructions on how to set a DASD online persistently, see Persistently setting DASDs online. When you work with DASDs, use the persistent device symbolic links under /dev/disk/by-path/
.
21.3. Preparing a new DASD with low-level formatting
Once the disk is online, change back to the /root
directory and low-level format the device. This is only required once for a DASD during its entire lifetime:
#
cd /root#
dasdfmt -b 4096 -d cdl -p /dev/disk/by-path/ccw-0.0.4b2e Drive Geometry: 10017 Cylinders * 15 Heads = 150255 Tracks I am going to format the device /dev/disk/by-path/ccw-0.0.4b2e in the following way: Device number of device : 0x4b2e Labelling device : yes Disk label : VOL1 Disk identifier : 0X4B2E Extent start (trk no) : 0 Extent end (trk no) : 150254 Compatible Disk Layout : yes Blocksize : 4096 --->> ATTENTION! <<--- All data of that device will be lost. Type "yes" to continue, no will leave the disk untouched: yes cyl 97 of 3338 |#----------------------------------------------| 2%
When the progress bar reaches the end and the format is complete, dasdfmt prints the following output:
Rereading the partition table... Exiting...
Now, use fdasd to partition the DASD. You can create up to three partitions on a DASD. In our example here, we create one partition spanning the whole disk:
# fdasd -a /dev/disk/by-path/ccw-0.0.4b2e reading volume label ..: VOL1 reading vtoc ..........: ok auto-creating one partition for the whole disk... writing volume label... writing VTOC... rereading partition table...
After a (low-level formatted) DASD is online, it can be used like any other disk under Linux. For example, you can create file systems, LVM physical volumes, or swap space on its partitions, for example /dev/disk/by-path/ccw-0.0.4b2e-part1
. Never use the full DASD device (dev/dasdb
) for anything but the commands dasdfmt
and fdasd
. If you want to use the entire DASD, create one partition spanning the entire drive as in the fdasd
example above.
To add additional disks later without breaking existing disk entries in, for example, /etc/fstab
, use the persistent device symbolic links under /dev/disk/by-path/
.
21.4. Persistently setting DASDs online
The above instructions described how to activate DASDs dynamically in a running system. However, such changes are not persistent and do not survive a reboot. Making changes to the DASD configuration persistent in your Linux system depends on whether the DASDs belong to the root file system. Those DASDs required for the root file system need to be activated very early during the boot process by the initramfs
to be able to mount the root file system.
The cio_ignore
commands are handled transparently for persistent device configurations and you do not need to free devices from the ignore list manually.
21.5. DASDs that are part of the root file system
The file you have to modify to add DASDs that are part of the root file system has changed in Red Hat Enterprise Linux 8. Instead of editing the /etc/zipl.conf
file, the new file to be edited, and its location, may be found by running the following commands:
# machine_id=$(cat /etc/machine-id) # kernel_version=$(uname -r) # ls /boot/loader/entries/$machine_id-$kernel_version.conf
There is one boot option to activate DASDs early in the boot process: rd.dasd=
. This option takes a Direct Access Storage Device (DASD) adapter device bus identifier. For multiple DASDs, specify the parameter multiple times, or use a comma separated list of bus IDs. To specify a range of DASDs, specify the first and the last bus ID. Below is an example of the /boot/loader/entries/4ab74e52867b4f998e73e06cf23fd761-4.18.0-80.el8.s390x.conf
file for a system that uses physical volumes on partitions of two DASDs for an LVM volume group vg_devel1
that contains a logical volume lv_root
for the root file system.
title Red Hat Enterprise Linux (4.18.0-80.el8.s390x) 8.0 (Ootpa) version 4.18.0-80.el8.s390x linux /boot/vmlinuz-4.18.0-80.el8.s390x initrd /boot/initramfs-4.18.0-80.el8.s390x.img options root=/dev/mapper/vg_devel1-lv_root crashkernel=auto rd.dasd=0.0.0200 rd.dasd=0.0.0207 rd.lvm.lv=vg_devel1/lv_root rd.lvm.lv=vg_devel1/lv_swap cio_ignore=all,!condev rd.znet=qeth,0.0.0a00,0.0.0a01,0.0.0a02,layer2=1,portno=0 id rhel-20181027190514-4.18.0-80.el8.s390x grub_users $grub_users grub_arg --unrestricted grub_class kernel
To add another physical volume on a partition of a third DASD with device bus ID 0.0.202b
. To do this, add rd.dasd=0.0.202b
to the parameters line of your boot kernel in /boot/loader/entries/4ab74e52867b4f998e73e06cf23fd761-4.18.0-32.el8.s390x.conf
:
title Red Hat Enterprise Linux (4.18.0-80.el8.s390x) 8.0 (Ootpa) version 4.18.0-80.el8.s390x linux /boot/vmlinuz-4.18.0-80.el8.s390x initrd /boot/initramfs-4.18.0-80.el8.s390x.img options root=/dev/mapper/vg_devel1-lv_root crashkernel=auto rd.dasd=0.0.0200 rd.dasd=0.0.0207 rd.dasd=0.0.202b rd.lvm.lv=vg_devel1/lv_root rd.lvm.lv=vg_devel1/lv_swap cio_ignore=all,!condev rd.znet=qeth,0.0.0a00,0.0.0a01,0.0.0a02,layer2=1,portno=0 id rhel-20181027190514-4.18.0-80.el8.s390x grub_users $grub_users grub_arg --unrestricted grub_class kernel
Make sure the length of the kernel command line in the configuration file does not exceed 896 bytes. Otherwise, the boot loader cannot be saved, and the installation fails.
Run zipl
to apply the changes of the configuration file for the next IPL:
# zipl -V Using config file '/etc/zipl.conf' Using BLS config file '/boot/loader/entries/4ab74e52867b4f998e73e06cf23fd761-4.18.0-80.el8.s390x.conf' Target device information Device..........................: 5e:00 Partition.......................: 5e:01 Device name.....................: dasda Device driver name..............: dasd DASD device number..............: 0201 Type............................: disk partition Disk layout.....................: ECKD/compatible disk layout Geometry - heads................: 15 Geometry - sectors..............: 12 Geometry - cylinders............: 13356 Geometry - start................: 24 File system block size..........: 4096 Physical block size.............: 4096 Device size in physical blocks..: 262152 Building bootmap in '/boot' Building menu 'zipl-automatic-menu' Adding #1: IPL section '4.18.0-80.el8.s390x' (default) initial ramdisk...: /boot/initramfs-4.18.0-80.el8.s390x.img kernel image......: /boot/vmlinuz-4.18.0-80.el8.s390x kernel parmline...: 'root=/dev/mapper/vg_devel1-lv_root crashkernel=auto rd.dasd=0.0.0200 rd.dasd=0.0.0207 rd.dasd=0.0.202b rd.lvm.lv=vg_devel1/lv_root rd.lvm.lv=vg_devel1/lv_swap cio_ignore=all,!condev rd.znet=qeth,0.0.0a00,0.0.0a01,0.0.0a02,layer2=1,portno=0' component address: kernel image....: 0x00010000-0x0049afff parmline........: 0x0049b000-0x0049bfff initial ramdisk.: 0x004a0000-0x01a26fff internal loader.: 0x0000a000-0x0000cfff Preparing boot menu Interactive prompt......: enabled Menu timeout............: 5 seconds Default configuration...: '4.18.0-80.el8.s390x' Preparing boot device: dasda (0201). Syncing disks... Done.
21.6. DASDs that are not part of the root file system
Direct Access Storage Devices (DASDs) that are not part of the root file system, that is, data disks, are persistently configured in the /etc/dasd.conf
file. This file contains one DASD per line, where each line begins with the DASD’s bus ID.
When adding a DASD to the /etc/dasd.conf
file, use key-value pairs to specify the options for each entry. Separate the key and its value with an equal (=) sign. When adding multiple options, use a space or a tab to separate each option.
Example /etc/dasd.conf
file
0.0.0207 0.0.0200 use_diag=1 readonly=1
Changes to the /etc/dasd.conf
file take effect after a system reboot or after a new DASD is dynamically added by changing the system’s I/O configuration (that is, the DASD is attached under z/VM).
Alternatively, to activate a DASD that you have added to the /etc/dasd.conf
file, complete the following steps:
Remove the DASD from the list of ignored devices and make it visible using the
cio_ignore
utility:# cio_ignore -r device_number
where
device_number
is the DASD device number.For example, if the device number is
021a
, run:# cio_ignore -r 021a
Activate the DASD by writing to the device’s
uevent
attribute:# echo add > /sys/bus/ccw/devices/dasd-bus-ID/uevent
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
21.7. FCP LUNs that are part of the root file system
The only file you have to modify for adding FCP LUNs that are part of the root file system has changed in Red Hat Enterprise Linux 8. Instead of editing the /etc/zipl.conf
file, the new file to be edited, and its location, may be found by running the following commands:
# machine_id=$(cat /etc/machine-id) # kernel_version=$(uname -r) # ls /boot/loader/entries/$machine_id-$kernel_version.conf
Red Hat Enterprise Linux provides a parameter to activate FCP LUNs early in the boot process: rd.zfcp=
. The value is a comma-separated list containing the FCP device bus ID, the target WWPN as 16 digit hexadecimal number prefixed with 0x
, and the FCP LUN prefixed with 0x and padded with zeroes to the right to have 16 hexadecimal digits.
The WWPN and FCP LUN values are only necessary if the zFCP
device is not configured in NPIV mode, when auto LUN scanning is disabled by the zfcp.allow_lun_scan=0
kernel module parameter or when installing RHEL-8.6 or older releases. Otherwise they can be omitted, for example, rd.zfcp=0.0.4000
. Below is an example of the /boot/loader/entries/4ab74e52867b4f998e73e06cf23fd761-4.18.0-80.el8.s390x.conf
file for a system that uses physical volumes on partitions of two FCP LUNs for an LVM volume group vg_devel1
that contains a logical volume lv_root
for the root file system. For simplicity, the example shows a configuration without multipathing.
title Red Hat Enterprise Linux (4.18.0-32.el8.s390x) 8.0 (Ootpa) version 4.18.0-32.el8.s390x linux /boot/vmlinuz-4.18.0-32.el8.s390x initrd /boot/initramfs-4.18.0-32.el8.s390x.img options root=/dev/mapper/vg_devel1-lv_root crashkernel=auto rd.zfcp=0.0.fc00,0x5105074308c212e9,0x401040a000000000 rd.zfcp=0.0.fc00,0x5105074308c212e9,0x401040a100000000 rd.lvm.lv=vg_devel1/lv_root rd.lvm.lv=vg_devel1/lv_swap cio_ignore=all,!condev rd.znet=qeth,0.0.0a00,0.0.0a01,0.0.0a02,layer2=1,portno=0 id rhel-20181027190514-4.18.0-32.el8.s390x grub_users $grub_users grub_arg --unrestricted grub_class kernel
-
To add another physical volume on a partition of a third FCP LUN with device bus ID 0.0.fc00, WWPN 0x5105074308c212e9 and FCP LUN 0x401040a300000000, add
rd.zfcp=0.0.fc00,0x5105074308c212e9,0x401040a300000000
to the parameters line of your boot kernel in/boot/loader/entries/4ab74e52867b4f998e73e06cf23fd761-4.18.0-32.el8.s390x.conf
. For example:
title Red Hat Enterprise Linux (4.18.0-32.el8.s390x) 8.0 (Ootpa) version 4.18.0-32.el8.s390x linux /boot/vmlinuz-4.18.0-32.el8.s390x initrd /boot/initramfs-4.18.0-32.el8.s390x.img options root=/dev/mapper/vg_devel1-lv_root crashkernel=auto rd.zfcp=0.0.fc00,0x5105074308c212e9,0x401040a000000000 rd.zfcp=0.0.fc00,0x5105074308c212e9,0x401040a100000000 rd.zfcp=0.0.fc00,0x5105074308c212e9,0x401040a300000000 rd.lvm.lv=vg_devel1/lv_root rd.lvm.lv=vg_devel1/lv_swap cio_ignore=all,!condev rd.znet=qeth,0.0.0a00,0.0.0a01,0.0.0a02,layer2=1,portno=0 id rhel-20181027190514-4.18.0-32.el8.s390x grub_users $grub_users grub_arg --unrestricted grub_class kernel
Make sure the length of the kernel command line in the configuration file does not exceed 896 bytes. Otherwise, the boot loader cannot be saved, and the installation fails.
-
Run
dracut -f
to update the initial RAM disk of your target kernel. -
Run
zipl
to apply the changes of the configuration file for the next IPL:
# zipl -V Using config file '/etc/zipl.conf' Using BLS config file '/boot/loader/entries/4ab74e52867b4f998e73e06cf23fd761-4.18.0-32.el8.s390x.conf' Target device information Device..........................: 08:00 Partition.......................: 08:01 Device name.....................: sda Device driver name..............: sd Type............................: disk partition Disk layout.....................: SCSI disk layout Geometry - start................: 2048 File system block size..........: 4096 Physical block size.............: 512 Device size in physical blocks..: 10074112 Building bootmap in '/boot/' Building menu 'rh-automatic-menu' Adding #1: IPL section '4.18.0-32.el8.s390x' (default) kernel image......: /boot/vmlinuz-4.18.0-32.el8.s390x kernel parmline...: 'root=/dev/mapper/vg_devel1-lv_root crashkernel=auto rd.zfcp=0.0.fc00,0x5105074308c212e9,0x401040a000000000 rd.zfcp=0.0.fc00,0x5105074308c212e9,0x401040a100000000 rd.zfcp=0.0.fc00,0x5105074308c212e9,0x401040a300000000 rd.lvm.lv=vg_devel1/lv_root rd.lvm.lv=vg_devel1/lv_swap cio_ignore=all,!condev rd.znet=qeth,0.0.0a00,0.0.0a01,0.0.0a02,layer2=1,portno=0' initial ramdisk...: /boot/initramfs-4.18.0-32.el8.s390x.img component address: kernel image....: 0x00010000-0x007a21ff parmline........: 0x00001000-0x000011ff initial ramdisk.: 0x02000000-0x028f63ff internal loader.: 0x0000a000-0x0000a3ff Preparing boot device: sda. Detected SCSI PCBIOS disk layout. Writing SCSI master boot record. Syncing disks... Done.
21.8. FCP LUNs that are not part of the root file system
FCP LUNs that are not part of the root file system, such as data disks, are persistently configured in the file /etc/zfcp.conf
. It contains one FCP LUN per line. Each line contains the device bus ID of the FCP adapter, the target WWPN as 16 digit hexadecimal number prefixed with 0x
, and the FCP LUN prefixed with 0x
and padded with zeroes to the right to have 16 hexadecimal digits, separated by a space or tab.
The WWPN and FCP LUN values are only necessary if the zFCP
device is not configured in NPIV mode, when auto LUN
scanning is disabled by the zfcp.allow_lun_scan=0
kernel module parameter or when installing RHEL-8.6 or older releases. Otherwise they can be omitted and only the device bus ID is mandatory.
Entries in /etc/zfcp.conf
are activated and configured by udev when an FCP adapter is added to the system. At boot time, all FCP adapters visible to the system are added and trigger udev.
Example content of /etc/zfcp.conf
:
0.0.fc00 0x5105074308c212e9 0x401040a000000000 0.0.fc00 0x5105074308c212e9 0x401040a100000000 0.0.fc00 0x5105074308c212e9 0x401040a300000000 0.0.fcd0 0x5105074308c2aee9 0x401040a000000000 0.0.fcd0 0x5105074308c2aee9 0x401040a100000000 0.0.fcd0 0x5105074308c2aee9 0x401040a300000000 0.0.4000 0.0.5000
Modifications of /etc/zfcp.conf
only become effective after a reboot of the system or after the dynamic addition of a new FCP channel by changing the system’s I/O configuration (for example, a channel is attached under z/VM). Alternatively, you can trigger the activation of a new entry in /etc/zfcp.conf
for an FCP adapter which was previously not active, by executing the following commands:
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_numberReplace device_number with the device number of the FCP adapter. For example:
#
cio_ignore -r fcfcTo trigger the uevent that activates the change, issue:
#
echo add > /sys/bus/ccw/devices/device-bus-ID/ueventFor example:
#
echo add > /sys/bus/ccw/devices/0.0.fcfc/uevent
21.9. Adding a qeth device
The qeth
network device driver supports 64-bit IBM Z OSA-Express features in QDIO mode, HiperSockets, z/VM guest LAN, and z/VM VSWITCH.
For more information about the qeth device driver naming scheme, see Customizing boot parameters.
21.10. Dynamically adding a qeth device
This section contains information about how to add a qeth
device dynamically.
Procedure
Determine whether the
qeth
device driver modules are loaded. The following example shows loadedqeth
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 qethIf the output of the
lsmod
command shows that theqeth
modules are not loaded, run themodprobe
command to load them:#
modprobe qethUse 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_idReplace 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 is0.0.f501
, and the data_device_bus_id is0.0.f502
:#
cio_ignore -r 0.0.f500,0.0.f501,0.0.f502Use 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 qethSelect 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)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)Now you can continue to configure the
encf500
network interface.
Alternatively, you can use sysfs
attributes to set the device online as follows:
Create a
qeth
group device:#
echo read_device_bus_id,write_device_bus_id,data_device_bus_id > /sys/bus/ccwgroup/drivers/qeth/groupFor example:
#
echo 0.0.f500,0.0.f501,0.0.f502 > /sys/bus/ccwgroup/drivers/qeth/groupNext, verify that the
qeth
group device was created properly by looking for the read channel:#
ls /sys/bus/ccwgroup/drivers/qeth/0.0.f500You 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
-
Bring the device online by writing
1
to the onlinesysfs
attribute:#
echo 1 > /sys/bus/ccwgroup/drivers/qeth/0.0.f500/onlineThen verify the state of the device:
#
cat /sys/bus/ccwgroup/drivers/qeth/0.0.f500/online 1A return value of
1
indicates that the device is online, while a return value0
indicates that the device is offline.Find the interface name that was assigned to the device:
#
cat /sys/bus/ccwgroup/drivers/qeth/0.0.f500/if_name encf500Now 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
21.11. Persistently adding a qeth device
To make your new qeth
device persistent, you need to create the configuration file for your new interface. The network interface configuration files are placed in the /etc/sysconfig/network-scripts/
directory.
The network configuration files use the naming convention ifcfg-device
, where device is the value found in the if_name
file in the qeth
group device that was created earlier, for example enc9a0
. The cio_ignore
commands are handled transparently for persistent device configurations and you do not need to free devices from the ignore list manually.
If a configuration file for another device of the same type already exists, the simplest way to add the config file is to copy it to the new name and then edit it:
#
cd /etc/sysconfig/network-scripts#
cp ifcfg-enc9a0 ifcfg-enc600
To learn IDs of your network devices, use the lsqeth utility:
#
lsqeth -p
devices CHPID interface cardtype port chksum prio-q'ing rtr4 rtr6 lay'2 cnt
-------------------------- ----- ---------------- -------------- ---- ------ ---------- ---- ---- ----- -----
0.0.09a0/0.0.09a1/0.0.09a2 x00 enc9a0 Virt.NIC QDIO 0 sw always_q_2 n/a n/a 1 64
0.0.0600/0.0.0601/0.0.0602 x00 enc600 Virt.NIC QDIO 0 sw always_q_2 n/a n/a 1 64
If you do not have a similar device defined, you must create a new file. Use this example of /etc/sysconfig/network-scripts/ifcfg-0.0.09a0
as a template:
# IBM QETH DEVICE=enc9a0 BOOTPROTO=static IPADDR=10.12.20.136 NETMASK=255.255.255.0 ONBOOT=yes NETTYPE=qeth SUBCHANNELS=0.0.09a0,0.0.09a1,0.0.09a2 PORTNAME=OSAPORT OPTIONS='layer2=1 portno=0' MACADDR=02:00:00:23:65:1a TYPE=Ethernet
Edit the new ifcfg-0.0.0600
file as follows:
-
Modify the
DEVICE
statement to reflect the contents of theif_name
file from yourccw
group. -
Modify the
IPADDR
statement to reflect the IP address of your new interface. -
Modify the
NETMASK
statement as needed. -
If the new interface is to be activated at boot time, then make sure
ONBOOT
is set toyes
. -
Make sure the
SUBCHANNELS
statement matches the hardware addresses for your qeth device. -
Modify the
PORTNAME
statement or leave it out if it is not necessary in your environment. You can add any valid
sysfs
attribute and its value to theOPTIONS
parameter. The Red Hat Enterprise Linux installation program currently uses this to configure the layer mode (layer2
) and the relative port number (portno
) ofqeth
devices.The
qeth
device driver default for OSA devices is now layer 2 mode. To continue using oldifcfg
definitions that rely on the previous default of layer 3 mode, addlayer2=0
to theOPTIONS
parameter.
/etc/sysconfig/network-scripts/ifcfg-0.0.0600
# IBM QETH DEVICE=enc600 BOOTPROTO=static IPADDR=192.168.70.87 NETMASK=255.255.255.0 ONBOOT=yes NETTYPE=qeth SUBCHANNELS=0.0.0600,0.0.0601,0.0.0602 PORTNAME=OSAPORT OPTIONS='layer2=1 portno=0' MACADDR=02:00:00:b3:84:ef TYPE=Ethernet
Changes to an ifcfg
file only become effective after rebooting the system or after the dynamic addition of new network device channels by changing the system’s I/O configuration (for example, attaching under z/VM). Alternatively, you can trigger the activation of a ifcfg
file for network channels which were previously not active yet, by executing the following commands:
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_idReplace 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 is0.0.0601
, and the data_device_bus_id is0.0.0602
:#
cio_ignore -r 0.0.0600,0.0.0601,0.0.0602To trigger the uevent that activates the change, issue:
#
echo add > /sys/bus/ccw/devices/read-channel/ueventFor example:
#
echo add > /sys/bus/ccw/devices/0.0.0600/ueventCheck the status of the network device:
#
lsqethNow start the new interface:
#
ifup enc600Check 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 foreverCheck 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 192.168.122.1Verify 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-
If the default route information has changed, you must also update
/etc/sysconfig/network
accordingly.
Additional resources
-
nm-settings-keyfile
man page on your system
21.12. Configuring an 64-bit IBM Z network device for network root file system
To add a network device that is required to access the root file system, you only have to change the boot options. The boot options can be in a parameter file, however, the /etc/zipl.conf
file no longer contains specifications of the boot records. The file that needs to be modified can be located using the following commands:
# machine_id=$(cat /etc/machine-id) # kernel_version=$(uname -r) # ls /boot/loader/entries/$machine_id-$kernel_version.conf
Dracut, the mkinitrd successor that provides the functionality in the initramfs that in turn replaces initrd, provides a boot parameter to activate network devices on 64-bit IBM Z early in the boot process: rd.znet=
.
As input, this parameter takes a comma-separated list of the NETTYPE
(qeth, lcs, ctc), two (lcs, ctc) or three (qeth) device bus IDs, and optional additional parameters consisting of key-value pairs corresponding to network device sysfs attributes. This parameter configures and activates the 64-bit IBM Z network hardware. The configuration of IP addresses and other network specifics works the same as for other platforms. See the dracut documentation for more details.
The cio_ignore commands for the network channels are handled transparently on boot.
Example boot options for a root file system accessed over the network through NFS:
root=10.16.105.196:/nfs/nfs_root cio_ignore=all,!condev rd.znet=qeth,0.0.0a00,0.0.0a01,0.0.0a02,layer2=1,portno=0,portname=OSAPORT ip=10.16.105.197:10.16.105.196:10.16.111.254:255.255.248.0:nfs‑server.subdomain.domain:enc9a0:none rd_NO_LUKS rd_NO_LVM rd_NO_MD rd_NO_DM LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYTABLE=us