If you want to perform a task on one host with reference to other hosts, use the delegate_to keyword on a task. This is ideal for managing nodes in a load balanced pool or for controlling outage windows. You can use delegation with the serial keyword to control the number of hosts executing at one time:
A serial console connection to bare metal or virtual machine DB system allows you to manage and troubleshoot your system in single-user mode using an SSH connection, e.g. if the boot volume becomes full causing a standard SSH connection to fail with permission denied errors.
Also, these servers log all activities and maintain a backup for security purposes. The main reason to log activities is to update the administrators as and when the intranet gets attacked by an outsider. Further, the backup can be used even if a single log got tampered with or destroyed. The only way to keep the backup safe and secure is to connect the bastion host to a dedicated computer by means of a serial port. The purpose of introducing this connection is to monitor the backup log and keep it safe.
In the above example, STDOUT will be directed to the output fileTestJob.%J.stdout and STDERR directed to TestJob.%J.stderr. Youwill notice that the example is very similar to to theserial example.The important line is the module load command.That tells the cluster to load the R framework into the environment so jobs may use it. 1e1e36bf2d