Red Hat Knowledgebase

The QS-22, when not netbooting, needs to have a console speed defined, otherwise the console will be filled with what appear to be control characters (using kernel command line root=/dev/VolGroup00/LogVol00 ro console=ttyS0 rhgb quiet console=hvc0 ro). There are two places the console speed must be specified: /etc/inittab file and /etc/yaboot.conf.

/etc/inittab should be changed as follows:

1. Comment out this line: co:2345:respawn:/sbin/agetty ttyS0 115200 vt100-nav
2. Add in this line: tty:2345:respawn:/sbin/agetty ttyS0 19200 vt100-nav

/etc/yaboot.conf's kernel boot line should be changed from append="console=ttyS0 rhgb quiet" to append="console=ttyS0,19200 rhgb quiet"

How can you do this, if the console is unusable? Networking to the system should be setup by default, so you can ssh to the system after install and set the console parameters correctly. If you have many systems with networking, you can use a script to ssh to each. If you are unable to use networking, you can break into the install at the end (before the reboot) using CTRL-z and edit the files rooted under /mnt/sysimage. If you are installing many systems, you can script this as part of your kickstart file.

More information can be found at IBM's retain tip H106643.