DRBD

DRBD is the service used for synchronisation of data (usually web and database files) on a cluster or HA solution. Not to be confused with Unision (which is typically used for synchronisation of config files due to not updating files as quickly as DRBD).

Installing

yum install drbd-utils* drbd-dkms

apt-get install drbd-utils* drbd-dkms

may need to add repos for this.

The above installs both the DRBD service files, as well as the required kernel module.