Be sure to take into consideration the potential security implications of storing every detail from every management session conducted by serial. By nature of the interface, most will be root/sudoer logins.

On a fresh Red Hat/CentOS dom0 you will find /var/log/xen/console/ barren, or perhaps not even extant (mkdir -P). On older installations that come with a xend service, you can enable serial console recording globally (all domUs at once) by setting XENCONSOLED_LOG_GUESTS=yes in /etc/sysconfig/xend and restarting the xend service.

XENCONSOLED_LOG_HYPERVISOR=yes XENCONSOLED_TIMESTAMP_HYPERVISOR_LOG=yes XENCONSOLED_LOG_GUESTS=yes XENCONSOLED_TIMESTAMP_GUEST_LOG=yes XENCONSOLED_LOG_DIR=/var/log/xen/console/

On newer system.d installations run out of xencommons I had to run down the environment variables:

locate xenconsoled.service /etc/systemd/system/multi-user.target.wants/xenconsoled.service /usr/lib/systemd/system/xenconsoled.service cat /usr/lib/systemd/system/xenconsoled.service [Unit] Description=Xenconsoled - handles logging from guest consoles and hypervisor Requires=proc-xen.mount xenstored.service After=proc-xen.mount xenstored.service ConditionPathExists=/proc/xen/capabilities [Service] Type=simple Environment=XENCONSOLED_ARGS= Environment=XENCONSOLED_TRACE=none Environment=XENCONSOLED_LOG_DIR=/var/log/xen/console EnvironmentFile=/etc/sysconfig/xencommons ExecStartPre=/bin/grep -q control_d /proc/xen/capabilities ExecStartPre=/bin/mkdir -p ${XENCONSOLED_LOG_DIR} ExecStart=/usr/sbin/xenconsoled -i --log=${XENCONSOLED_TRACE} --log-dir=${XENCONSOLED_LOG_DIR} $XENCONSOLED_ARGS [Install] WantedBy=multi-user.target xenconsoled --help Usage: xenconsoled [-h] [-V] [-v] [-i] [--log=none|guest|hv|all] [--log-dir=DIR] [--pid-file=PATH] [-t, --timestamp=none|guest|hv|all] [-o, --overflow-data=discard|keep]
Documentation regarding xenconsoled's options is scarce to say the least. At the time of publication I'm apparently the first person on the internet to have tried figuring out what important-sounding --overflow-data does. Fortunately xenconsoled plays nicely with being killed live on the command line and having its flags twiddled with - it will even auto-daemonize. Avoid spawning more than one instance at a time, though doing so produces no catastrophically ill effects.

Once you have settled on a configuration, it is made persistent by dropping environment variables into the very top of /etc/sysconfig/xencommons:

## Path: System/Virtualization ## Type: string ## Default: "none" # # Log xenconsoled messages (cf xl dmesg) #XENCONSOLED_TRACE=[none|guest|hv|all] XENCONSOLED_TRACE=all XENCONSOLED_ARGS="--timestamp=all" #XENCONSOLED_LOG_DIR=/var/log/xen/console

On Debian and derivatives like Ubuntu the same is accomplished by setting:
XENCONSOLED_ARGS="--timestamp=all --log=all --log-dir=/var/log/xen/console/"
in /etc/default/xend.

Another option is the direct route:
nohup xl console domain 2>&1 tee /var/log/xen/console/guest-domain.log &

Note that the actual client interface, xenconsole can be called directly, but typically is not in your PATH by default and must be called from its location. It accepts a domain ID number as opposed to a domain name, but allows one to specify if the interface to which you are connecting is provided by HVM/QEMU (serial) or PV (pv) using the --type flag:

/usr/lib64/xen/bin/xenconsole --help Usage: /usr/lib64/xen/bin/xenconsole [OPTION] DOMID Attaches to a virtual domain console -h, --help display this help and exit -n, --num N use console number N --type TYPE console type. must be 'pv' or 'serial' --start-notify-fd N file descriptor used to notify parent xl list | grep domain domain 5 8192 5 -b---- 119.1 /usr/lib64/xen/bin/xenconsole 5

You can tee your interactive session to a logfile, but unlike the configuration shown above the flow into the file will cease when you exit xenconsole:

/usr/lib64/xen/bin/xenconsole 5 tee:stdio,file:/var/log/xen/console/guest-domain.log

Some interesting and highly technical background on the provisioning and configuration of the underlaying serial devices and emulations is provided in https://xenbits.xenproject.org/docs/unstable/misc/console.txt however you are unlikely to find it useful to your logging endeavour unless you are engaged in extreme debugging.