20.8. 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-9.0 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: