Logging & Debugging

OpenNebula provides logs for many resources. It supports three logging systems: file based logging systems, syslog logging and logging to the standard error stream.

In the case of file based logging, OpenNebula keeps separate log files for each active component, all of them stored in /var/log/one. To help users and administrators find and solve problems, they can also access some of the error messages from the CLI or the Sunstone GUI.

With syslog or standard error, the logging strategy is almost identical, except that the logging messages slightly change their format following syslog logging conventions and resource information.

Configure the Logging System

The Logging system can be changed in /etc/one/oned.conf, specifically under the LOG section. Two parameters can be changed: SYSTEM, which is ‘syslog’, ‘file’ (default) or ‘std’, and the DEBUG_LEVEL is the logging verbosity.

For the scheduler the logging system can be changed in the exact same way. In this case the configuration is in /etc/one/sched.conf.

Log Resources

There are different log resources corresponding to different OpenNebula components:

  • ONE Daemon: The core component of OpenNebula dumps all its logging information onto /var/log/one/oned.log. Its verbosity is regulated by DEBUG_LEVEL in /etc/one/oned.conf. By default the ONE start up scripts will backup the last oned.log file using the current time, e.g. oned.log.20121011151807. Alternatively, this resource can be logged to the syslog.
  • Scheduler: All the scheduler information is collected into the /var/log/one/sched.log file. This resource can also be logged to the syslog.
  • Virtual Machines: The information specific to a VM will be dumped into the log file /var/log/one/<vmid>.log. All VMs controlled by OpenNebula have their own directory, /var/lib/one/vms/<VID> if syslog/stderr isn’t enabled. You can find the following information in it:
    • Deployment description files : Stored in deployment.<EXECUTION>, where <EXECUTION> is the sequence number in the execution history of the VM (deployment.0 for the first host, deployment.1 for the second and so on).
    • Transfer description files : Stored in transfer.<EXECUTION>.<OPERATION>, where <EXECUTION> is the sequence number in the execution history of the VM, and <OPERATION> is the stage where the script was used, e.g. transfer.0.prolog, transfer.0.epilog, or transfer.1.cleanup.
  • Drivers: Each driver can have its ONE_MAD_DEBUG variable activated in RC files. If so, error information will be dumped to /var/log/one/name-of-the-driver-executable.log. Log information from the drivers is in oned.log.

Otherwise, the information is sent to syslog/stderr.

Logging Format

The structure of an OpenNebula message for a file based logging system is the following:

date [Z<zone_id>][module][log_level]: message body

In the case of syslog it follows the standard:

date hostname process[pid]: [Z<zone_id>][module][log_level]: message

where the zone_id is the ID of the zone in the federation, 0 for single zone set ups, the module is any of the internal OpenNebula components: VMM, ReM, TM, etc., and the log_level is a single character indicating the log level: I for info, D for debug, etc.

For syslog, OpenNebula will also log the Virtual Machine events like this:

date hostname process[pid]: [VM id][Z<zone_id>][module][log_level]: message

and similarly for stderr logging.

For oned and VM events the formats are:

date [Z<zone_id>][module][log_level]: message
date [VM id][Z<zone_id>][module][log_level]: message

Virtual Machine Errors

Virtual Machine errors can be checked by the owner or an administrator using the onevm show output:

onevm show 0
ID                  : 0
NAME                : one-0
USER                : oneadmin
GROUP               : oneadmin
STATE               : ACTIVE
START TIME          : 07/19 17:44:20
END TIME            : 07/19 17:44:31
DEPLOY ID           : -

NET_TX              : 0
NET_RX              : 0
USED MEMORY         : 0
USED CPU            : 0

  TARGET=hdb ]
  MESSAGE="Error excuting image transfer script: Error copying /tmp/some_file to /var/lib/one/0/images/isofiles",
  TIMESTAMP="Tue Jul 19 17:44:31 2011" ]

 SEQ        HOSTNAME ACTION           START        TIME       PTIME
   0          host01   none  07/19 17:44:31 00 00:00:00 00 00:00:00

Here the error message that it could not copy a file most probably means the file does not exist.

Alternatively you can check the log files for the VM at /var/log/one/<vmid>.log.


Check the Virtual Machines High Availability Guide, to learn how to recover a VM in fail state.

Host Errors

Host errors can be checked executing the onehost show command:

onehost show 1
ID                    : 1
NAME                  : host01
STATE                 : ERROR
IM_MAD                : im_kvm
VM_MAD                : vmm_kvm
TM_MAD                : tm_shared

MAX MEM               : 0
USED MEM (REAL)       : 0
MAX CPU               : 0
USED CPU (REAL)       : 0
TOTAL VMS             : 0

  MESSAGE="Error monitoring host 1 : MONITOR FAILURE 1 Could not update remotes",
  TIMESTAMP="Tue Jul 19 17:17:22 2011" ]

The error message appears in the ERROR value of the monitoring. To get more information you can check /var/log/one/oned.log. For example for this error we get in the log file:

Tue Jul 19 17:17:22 2011 [InM][I]: Monitoring host host01 (1)
Tue Jul 19 17:17:22 2011 [InM][I]: Command execution fail: scp -r /var/lib/one/remotes/. host01:/var/tmp/one
Tue Jul 19 17:17:22 2011 [InM][I]: ssh: Could not resolve hostname host01: nodename nor servname provided, or not known
Tue Jul 19 17:17:22 2011 [InM][I]: lost connection
Tue Jul 19 17:17:22 2011 [InM][I]: ExitCode: 1
Tue Jul 19 17:17:22 2011 [InM][E]: Error monitoring host 1 : MONITOR FAILURE 1 Could not update remotes

From the execution output we notice that the host name is not known, probably due to a mistake naming the host.