fedora 31 : parallel ssh program pssh Hint

# yum install pssh -y


# man pssh

Connect to host1 and host2, and print "hello, world" from each:

     pssh -i -H "host1 host2" echo "hello, world"


Print "hello, world" from each host specified in the file hosts.txt:

     pssh -i -h hosts.txt echo "hello, world"


Run a command as root with a prompt for the root password:

     pssh -i -h hosts.txt -A -l root echo hi


Run a long command without timing out:

     pssh -i -h hosts.txt -t 0 sleep 10000


If  the file hosts.txt has a large number of entries, say 100, then the parallelism option

may also be set to 100 to ensure that the commands are run concurrently:

     pssh -i -h hosts.txt -p 100 -t 0 sleep 10000


Run a command without checking or saving host keys:

     pssh -i -H host1  -H  host2  -x  "-O  StrictHostKeyChecking=no  -O  UserKnownHosts‐

     File=/dev/null -O GlobalKnownHostsFile=/dev/null" echo hi


Print the node number for each connection (this will print 0, 1, and 2):

     pssh -i -H host1 -H host1 -H host2 'echo $PSSH_NODENUM'


If you have a set of hosts that you connect to frequently with specific options, it may be

helpful to create an alias such as:

     alias pssh_servers="pssh -h /path/to/server_list.txt -l root -A"




# vi /root/.ssh/test_servers




# vi /root/.bashrc

alias psshMyServers="pssh -h /root/.ssh/test_servers -x '-q -o StrictHostKeyChecking=no -o PreferredAuthentications=publickey -o PubkeyAuthentication=yes' "


# . /root/.bashrc

psshMyServers -i  'uptime; hostname -f'