Truck based replication, also known as disk shipping, is a means of preseeding a remote site with data to be replicated, by physically shipping storage media to the remote site. This is particularly suited for situations where
- the total amount of data to be replicated is fairly large (more than a few hundreds of gigabytes);
- the expected rate of change of the data to be replicated is less than enormous;
- the available network bandwidth between sites is limited.
In such situations, without truck based replication, DRBD would require a very long initial device synchronization (on the order of weeks, months, or years). Truck based replication allows to ship a data seed to the remote site, and so drastically reduces the initial synchronization time. See Section 5.1.8, “Using truck based replication” for details on this use case.