Managing many hosts is quite challenging task. There are many tools to solve the problem. My favorite is pdsh.
Running a command across a set of hosts is as simple as following:
# pdsh -w 192.168.177.[201-208] -R ssh reboot
Together with dshbak (which is a part of pdsh package) you can do even cooler things. Like, check which systems have yum:
# pdsh -w 192.168.177.[201-208] -R ssh "which yum" | dshbak -c ---------------- 192.168.177.[201-203] ---------------- /usr/bin/yum
Or which systems run older version of MySQL
# pdsh -w 192.168.177.[201-208] -R ssh "mysql -e \"SHOW VARIABLES LIKE 'version'\"" | dshbak -c ---------------- 192.168.177.[201-203] ---------------- Variable_name Value version 5.6.19 ---------------- 192.168.177.[204-208] ---------------- Variable_name Value version 5.5.38
To make pdsh …
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