Description of problem: When booting a machine enabled for serial console use, xen does not write to the console during the boot. Version-Release number of selected component (if applicable): 0303 build of the -83 kernel How reproducible: configure the serial port in BIOS, making sure to DISABLE console redirection after boot (so 2.6 can take over). Mine was wired for 38400, RTS/DTS, direct, 8/1/none using minicom (or some such) and a null modem cable, hook up the serial port, so you can observe the output. Steps to Reproduce: 1. configure /etc/inittab with a line like: s0:2345:respawn:/sbin/agetty -L -f /etc/issueserial 38400 ttyS0 vt100 add "console=ttyS0, 38400 to both the xen and non-xen kernel entries 2. Boot the machine with the xen kernel 3. Boot the machine with the regular kernel Actual results: When booting with the xen kernel, nothing gets written to ttyS0 after the 'initrd' message. However, it works fine with the bare iron kernel. Expected results: Additional info:
Hm, what do you mean by "nothing gets written to ttyS0 after the 'initrd' message"? Which initrd message are you talking about? This is almost certainly a configuration issue, since the Xen serial console behaves in different ways from the bare metal kernel. Basically what happens is that the hypervisor is in control of the serial hardware, and emulates one so that the dom0 kernel can also read/write to it. So what you need for configuration in /boot/grub/grub.conf is: title Red Hat Enterprise Linux Server (2.6.18-84.el5xen) root (hd0,0) kernel /xen.gz-2.6.18-84.el5 com1=115200,8n1 module /vmlinuz-2.6.18-84.el5xen ro root=/dev/HostGroup/RHEL5_x86_64 console=tty0 console=ttyS0,115200 module /initrd-2.6.18-84.el5xen.img Notice that the hypervisor line uses the "com1" syntax. Also notice that INIT messages all go out to the *last* console you specify, namely console=ttyS0, etc. Finally, if you had secondary serial port on this machine, you would change the HV configuration to something like "com2=115200,8n1 console=com2L", but you would *not* change the kernel line (it would still be ttyS0). This is because the serial port is emulated to the dom0. Make sure all of the above makes sense to you, and make sure you have it configured correctly; it is one of the hard things to get right when using Xen initially. Chris Lalancette
will give it a shot and get back to you thanks chris
the above changes worked. bug can be closed or withdrawn.
OK, cool. Chris Lalancette