Clustering

When you are administering a cluster you will need sudo permission, even with passwordless SSH you will find that some operations will require a password for usage and authentication, ie admin scripts on the nodes. there are two ways to get around this

1. Redirection
   1. Create a file with your password in your home directory, make it rwx only for you ie chmod ou-rwx <password file>
   2. in your admin script redirec the passwor call in the ssh command call
      1. ssh felcl${num} sudo shutdown -h now < ~/psswd &
   3. this will redirect and enter the pasword to all of the nodes that you are trying to access as sudoer.
2. Sudoers file
   1. The cleaner method is to create a sudoers file and allow the admins passworless sudo access
   2. You may think oh that easy, but the problem is that OS X sudoers file is not standard and dosent behave properly.
   3. after much experimentation and trial and error here is the proper /etc/sudoers file settings.