How to execute multiple commands during an SSH session?

How to execute multiple commands during an SSH session?

I have a local machine which is supposed to make an SSH session to a remote master machine and then another inner SSH session from the master to each of some remote slaves, and then execute 2 commands i.e. to delete a specific directory and recreate it.

What happens when you run SSH-T in a remote terminal?

When you run ssh -t, the remote command is running with a controlling terminal and thus the remote grep behaves like your local one. MultiTail allows you to monitor logfiles and command output in multiple windows in a terminal, colorize, filter and merge. You can checkout in’side log.

What can you do with SSH and output?

We also learned how to redirect the output back to our local system, which can effectively let us use SSH to make quick backups, file transfers, or even execute scripts remotely. We have only scraped the surface here, and these commands can be adjusted to accomplish any kind of remote execution task that you come up with.

How to read SSH hostnames from local machine?

Note that the local machine has passwordless SSH to the master and the master has passwordless SSH to the slaves. Also all hostnames are known in .ssh/config of the local/master machines and the hostnames of the slaves are in slaves.txt locally and I read them from there.

How to run multiple SSH commands in parallel?

Please note that the -t option will get rid of ” Sorry, you must have a tty to run sudo/insert your-command-here” error message. You can also use pssh (parallel ssh) for executing ssh in parallel on a number of Linux/Unix/BSD servers.

Can you remotely execute a command with SSH?

SSH not only allows you to connect to remote servers, you can use it to send an ad hoc command or commands to a remote server. This post will cover three different methods to remotely execute multi-line commands with SSH.

What does it mean to have multiple SSH connections?

Multiplexing is the ability to send more than one signal over a single line or connection. With multiplexing, OpenSSH can re-use an existing TCP connection for multiple concurrent SSH sessions rather than creating a new one each time.

How to run multiple programs with the mpirun command?

For an MPMD (Multiple Program, Multiple Data) application, the command syntax appears similar to the following: % mpirun[options] [program-name] :[options2] [program-name2] For example: % mpirun -npx program1:-npy program2 This command starts xnumber of copies of the program program1, and then starts ycopies of the program program2.

How to specify multiple host slots in mpirun?

To specify multiple slots with the -hostoption for each host repeat the host name on the command line for each slot you want to use. % mpirun -host node1,node1,node2,node2… If you are using a resource manager such as Sun Grid Engine or PBS, the resource manager maintains an accurate count of available slots.

Do you need a host list to run RSH / sshinstead?

If you are using rsh/sshinstead of a resource manager, you must use a hostfile or host list to identify the hosts on which the program will be run.