The development of this interface specification was led by Intel Corporation and is supported by more than two hundred computer systems vendors including Dell, Hewlett-Packard, Intel, and NEC Corporation.

1. Install the ipmitool which is used to send commands and receive information from the management interface.

apt-get install ipmitool


2. Use this command to send and receive information to a remote server

ipmitool -H {ip_address} -U {username} -a {ipmi_command}


You can also skip the "-a" parameter (which makes ipmitool prompt for a password everytime) and add "-P {password}" to avoid the password prompt.

Here are some examples of useful commands

Get hardware status (including hardware failures and power status)

ipmitool -H {ip_address} -U {username} -a chassis status


List all sensor values (including temperature, fan speed, voltage and more)

ipmitool -H {ip_address} -U {username} -a sensor list


Print system event log

ipmitool -H {ip_address} -U {username} -a sel list


Check if your server is on or off

ipmitool -H {ip_address} -U {username} -a chassis power status


Power off the server (soft shutdown via ACPI)

ipmitool -H {ip_address} -U {username} -a chassis power soft


Power off the server (hard)

ipmitool -H {ip_address} -U {username} -a chassis power off


Start the server

ipmitool -H {ip_address} -U {username} -a chassis power on


Restart server (hard)

ipmitool -H {ip_address} -U {username} -a chassis power reset


1. Install the Unison package

apt-get install unison


2. Configure the Unison defaults (pico /root/.unison/default.prf)

# skip asking for confirmations on non-conflicting changes
auto=true
 
# the user interface will ask no questions at all
batch=true
 
# Unison will request an extra confirmation if it appears that the entire replica has been deleted
confirmbigdeletes=true
 
# Unison will use the modification time and length of a file as a `pseudo inode number' when scanning replicas for updates, instead of reading the full cont$
fastcheck=true
 
# the group attributes of the files are synchronized
group=true
 
# the owner attributes of the files are synchronized
owner=true
 
# prefer newer version of files in case of conflicts
prefer=newer
 
# the textual user interface will print nothing at all, except in the case of errors.
silent=true
 
# file modification times (but not directory modtimes) are propagated.
times=true


A few of the configuration values will make Unsion silent so that no user action will be required to do the sync, deleted files will be moved to /var/backups/unison to avoid accidental deletion and if the same file is updated on both servers we'll keep the newer file.

3. Create a private key to avoid passphrase popup to be able to do automatic synchronization

ssh-keygen -t dsa


4. Copy the key to the remote machine

ssh-copy-id -i .ssh/id_dsa.pub user1@remote.machine.com


5. Manually synchronize a directory

unison /var/www ssh://remote.machine.com//var/www


This will sync /var/www between the local machine and remote.machine.com