1. Computer software which, when executed by appropriate processing means, causes the processing means to implement a method for replicating a filesystem between a first server and a second server prior to and following a partition between the first server and the second server, the method comprising: at the first server, taking snapshots of a current state of the filesystem at predetermined points in time following modification of the filesystem, each snapshot recording differences between the current state of the filesystem on the server and the state of the filesystem on the server at the time point of a previous snapshot; continually replicating the snapshots taken on the first server to the second server as soon as they are taken; upon detection of a partition, both the first and the second server becoming masters for the filesystem and accepting new modifications to the filesystems; after recovery of the partition, performing an update process to update the filesystem, the update process comprising: identifying which of the first server and the second server contains the most current version of the filesystem; nominating the server identified as containing the most current version of the filesystem as the master server and the other server as the slave server; identifying a snapshot that is common to both the master server and the slave server; and replicating subsequent snapshots from the master server to the slave server.