Init script output is not shown during startup when viewing Red Hat Enterprise Linux 6 from a serial console
Environment
Red Hat Enterprise Linux 6
Issue
Init script output is not shown during startup when viewing Red Hat Enterprise Linux 6 from a serial console.
Resolution
Update to dracut-004-283.el6 (from RHBA-2012-0839) or later, for this change:
* If the user adds multiple "console=[tty]" parameters on the kernel command
line, the last parameter specifies the primary console. Previously, dracut
failed to initialize this console and instead initialized /dev/tty0
unconditionally. This bug has been fixed and dracut now initializes the correct
console in the described scenario. (BZ#752073)
Do note that in addition to updating dracut, the kernel's initial RAM disk (initrd) needs to be regenerated for this fix to become effective.
Workaround
If init script loading status fails to show when using a serial console to view RHEL6 startup, the rd_NO_PLYMOUTH parameter must be added to the kernel line of /boot/grub/grub.conf. Here is an example grub.conf:
kernel /vmlinuz-2.6.32-131.12.1.el6.x86_64 ro root=/dev/mapper/vg0-LogVol01 rd_LVM_LV=vg0/LogVol01 rd_LVM_LV=vg0/swap rd_NO_LUKS rd_NO_MD rd_NO_DM LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYBOARDTYPE=pc KEYTABLE=us crashkernel=auto rhgb quiet console=tty0 console=ttyS0,115200 rd_NO_PLYMOUTH
Please note that the console=tty0 and console=ttyS0,115200 are required for serial console access, but will vary from environment to environment. For a better understanding of these parameters and RHEL6, please see the following knowledgebase article: How do I set up a serial terminal and/or console in Red Hat Enterprise Linux?.
This solution is part of Red Hat’s fast-track publication program, providing a huge library of solutions that Red Hat engineers have created while supporting our customers. To give you the knowledge you need the instant it becomes available, these articles may be presented in a raw and unedited form.
Comments