Patent ID: 8818951

Claim:
A method of creating a snapshot of a distributed file system comprising: quiescing requests affecting the distributed file system, the distributed file system including a first set of one or more metadata file systems storing metadata about files in the distributed file system and including a second set of one or more data file systems storing file content data for files of the distributed file system; obtaining a snapshot of each metadata file system in the first set; obtaining a snapshot of each data file system in the second set; and unquiescing requests affecting the distributed file system upon successful completion of said obtaining said snapshot for each metadata file system in the first set and upon successful completion of said obtaining said snapshot of each data file system in the second set, whereby the snapshot of the distributed file system is created as a result of successfully completing said first obtaining step and said second obtaining step and wherein the snapshot of the distributed file system includes the snapshot of each metadata file system in the first set and includes the snapshot of each data file system in the second set, and the method further comprising: recording information about processing steps performed in connection with creating the snapshot of the distributed file system and wherein, upon failure of a processing step performed in connection with creating the snapshot of the distributed file system as recorded, using said information recorded in connection with recovering from the failure of the processing step to undo one or more processing steps in connection with creating the snapshot of the distributed file system previously performed prior to the failure of the processing step, and, wherein, upon repeatedly failing a predetermined number of times to undo a first of the one or more processing steps, a background process performs cleanup processing to delete one or more snapshots of any of a metadata file system and a data file system, or portions thereof, created during the first processing step.