How to configure serial console access on a XEN based full virtual SLE VM

This document (7003720) is provided subject to the disclaimer at the end of this document.

Environment

SUSE Linux Enterprise Server 11
SUSE Linux Enterprise Server 10 Service Pack 2

Situation

By default a fully virtualized SUSE Linux Enterprise Server 10/11 virtual machine (VM) does not have serial console support enabled.
This prevents connecting to it using the

xm console <domain-id>

command.

Resolution

Follow these steps to enable it.

Log in to the VM
Append the parameter "console=ttyS0" to the kernel command line in the bootloader configuration (e.g. /boot/grub/menu.lst), so that it for instance looks like this :
kernel /boot/vmlinuz-2.6.16.60-0.39.3.PTF.509066.3-smp root=/dev/disk/by-id/ata-QEMU_HARDDISK_QM00001-part2 resume=/dev/hda1 splash=silent showopts console=ttyS0
Activate the following line in /etc/inittab by removing the leading # sign.
S0:12345:respawn:/sbin/agetty -L 9600 ttyS0 vt102
Allow login to the serial console by adding the following line to the /etc/securetty file :
ttyS0
Shut down the VM
Confirm that the configuration file of the the VM in /etc/xen/vm contains a line like
serial="pty"
If not, then add it and refresh the xenstore with the command
```
# xm new <vm-name>
```
Boot the VM and verify that serial console works with
```
# xm console <domain-id>
```

Additional Information

Disconnect from the terminal is done with the Ctrl-] key-kombination.
Keep in mind that the last line shown on the terminal (e.g. a login prompt) is not shown when connecting (since this is a serial console), so an extra Enter may be required.

In some configurations, the serial console may hang or get out of synchronization. This is a known bug - refer to Serial console synchronization problem and/or hanging (re)boot on full-virtual VMs

Disclaimer

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