Commvault Systems, Inc.
PRIVATE SNAPSHOTS BASED ON SPARSE FILES AND DATA REPLICATION

Abstract:

To overcome problems encountered with instability and/or risk of data corruption arising from using software snapshots, the present approach relies instead on data replication and sparse files to provide personal or private versions of a data storage volume ("private writable snapshots"). The disclosed technological solution avoids the use of software snapshot technologies altogether. Instead, a family of inter-related and cascading sparse files are maintained as data sources of replicated data volumes. In the event that the server which controls these sparse files crashes, the sparse files themselves are persistent and remain uncorrupted in a data storage platform, such as a storage array. An illustrative Internet Small Computer Systems Interface server ("ISCSI server") provides user computing devices with private writable snapshots of a desired volume of data using the illustrative sparse files.