# 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'