A system, method and computer readable medium for providing a standby file system
with snapshot feature is disclosed. A first snapshot of a primary file system is
generated. Next, a standby file system restores the first snapshot of the primary
file system in the standby file system and a snapshot of the standby file system
is taken. Then, a second snapshot of the primary file system is taken and a data
set capturing the differences between the first snapshot of the primary file system
and a previous data set of the primary file system is generated. Subsequently,
the data set is applied to the standby file system. Upon unavailability of the
primary file system, the standby file system is initialized as the new primary
file system. Upon recovery of the old primary file system, the old primary file
system is initialized as a new standby file system.