What were you trying to do that didn't work?

thorsten.diehl1 from IBM reported when they try to install Linux in z/VM machines using the CMSDASD option in the generic.prm as documented in RHEL 9 docs 9.7.2. 64-bit IBM z/VM configuration file
https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/9/html/automatically_installing_rhel/preparing-a-rhel-installation-on-64-bit-ibm-z_rhel-installer#ibm-zvm-configuration-file_parameters-and-configuration-files-on-ibm-z

The installation doesn't find the DASD, the installation can't continue

What is the impact of this issue to you?

Low, I can install on z/VM without CMS.

Please provide the package NVR for which the bug is seen:

dracut-057-70.git20240819.el9.s390x

How reproducible is this bug?:

100%

Steps to reproduce

1. Under z/VM use generic.prm

   Parmfile: 
   CMSDASD=191 CMSCONFFILE=rhel.conf
   inst.repo=http://172.18.10.1/redhat/s390x/RHEL9.5/DVD
   inst.vnc inst.vncpassword=xxxxxxxx

   with attached rhel.conf where the DASD identifier is 191

2. Start the installation with CMS, ref https://www.ibm.com/docs/en/SSB27U_7.4.0/pdf/hcpl0_v7r4.pdf

Expected results

The anaconda installer is loaded successfully and the installation can proceed with the selected DASD disk.

Actual results

systemd nm-wait-online-initrd.service is hanging for 90 seconds
vnc service available, disks can not be found. manual detection within anaconda doesn't work either.
ssh root@hostname: lscss shows the disks as not activated, but available.
/etc/dasd.conf is empty.

Additional info

From Thorsten:

When creating a dasd.conf manually and staring dasdconf.sh:

[anaconda root@a8315003 ~]# echo "0.0.c009" > /etc/dasd.conf
[anaconda root@a8315003 ~]# dasdconf.sh /etc/dasd.conf
[anaconda root@a8315003 ~]# lsdasd
Bus-ID    Status    Name      Device  Type         BlkSz  Size      Blocks
================================================================================
[anaconda root@a8315003 ~]# dasdconf.sh 
[anaconda root@a8315003 ~]# sh -x /sbin/dasdconf.sh 
+ '[' -z '' ']'
+ exit 0

/sbin/dasdconf.sh uses the variable $DEVPATH, and that seems to be empty.
Even if it was not empty, dasdconf.sh is not able to set the DASD online, because it uses the very old method via sysfs attribute to set it online. This does not work with RHEL9 any more.

[anaconda root@a8315003 ~]# lscss -d 0.0.c009
Device   Subchan.  DevType CU Type Use  PIM PAM POM  CHPIDs           
----------------------------------------------------------------------
0.0.c009 0.0.0001  3390/0c 3990/e9      f0  f0  ff   32333435 00000000
[anaconda root@a8315003 ~]# echo 1 > /sys/bus/ccw/drivers/dasd-eckd/0.0.c009/online
-bash: /sys/bus/ccw/drivers/dasd-eckd/0.0.c009/online: No such file or directory
[anaconda root@a8315003 ~]# ll /sys/bus/ccw/drivers/dasd-eckd/0.0.c009
ls: cannot access '/sys/bus/ccw/drivers/dasd-eckd/0.0.c009': No such file or directory
[anaconda root@a8315003 ~]# ll /sys/bus/ccw/drivers/dasd-eckd/
total 0
--w-------. 1 root root 4096 Nov 29 17:03 bind
lrwxrwxrwx. 1 root root    0 Nov 29 16:53 module -> ../../../../module/dasd_eckd_mod
--w-------. 1 root root 4096 Nov 29 16:49 uevent
--w-------. 1 root root 4096 Nov 29 16:49 unbind