A system and method to perform a system-wide file system image without time smear
in a distributed object-based data storage system. A realm manager is elected as
an image master using the Distributed Consensus Algorithm to execute image-taking.
All pending write capabilities are invalidated prior to taking the system-wide
file system image so as to quiesce the realm and prepare the storage system for
the system-wide image. Once the system is quiesced, the image master instructs
each storage manager in the system to clone each live object group contained therein
without explicitly cloning any objects contained in such object group. In one embodiment,
a file manager copies an object in the system before a write operation is performed
on that object after the image is taken. Neither the cloning operation nor the
copying operation update any directory objects in the system. At run time, a client
application may use a mapping scheme to access objects contained in the system-wide image.