File system capable of generating snapshots and providing fast sequential read access

A system, comprising:

• one or more storage devices including a storage space;
• a storage system having a processor and coupled to the storage devices, the storage system configured to provide storage services relating to the organization of information on the storage devices;
• a storage operating system executed by the processor and configured to generate a snapshot and providing sequential read access to a data container stored on the storage devices, the storage operating system further configured to apportion the storage space into regions, including a plurality of active regions and other regions, where each active region is allocated for a different sequential portion of the data container and configured to store active file system data and snapshot data for the different sequential portion of the data container, wherein first blocks in a portion of the active region are marked as one of active for use in an active file system, active for use in one or more snapshots, and free;
• and
• the storage operating system executed by the processor further configured to overwrite the active block within the active region with new active data if an active block is not required by the one or more snapshots, and the storage operating system executed by the processor further configured to preserve the active block to become a snapshot block of the data container and write the new active data to any block marked as free in the active region if the active block is required by the one or more snapshots.

Apparatus configured to provide an on-disk structure of a file system executed by a processor and including one or more disks, the file system capable of generating snapshots and providing fast sequential read access to a data container stored on the disks, comprising:

• means for arranging sequential portions of a data container into a plurality of regions on the disks, each region including a predetermined amount of disk space represented by blocks on the disks;
• means for organizing the plurality of regions as active regions and other regions, each active region allocated for a different sequential portion of the data container and containing active file system data and snapshot data for the different sequential portion of the data container, wherein first blocks in a portion of the active region are marked as one of active for use in an active file system, active for use in one or more snapshots, and free;
• means for overwriting an active block within the active region with new active data if the active block is not required by the one or more snapshots;
• and
• means for preserving the active block to become a snapshot block of the data container and means for writing the new active data to any block marked as free in the active region if the active block is required by the one or more snapshots.

A non-transitory computer readable medium containing executable program instructions executed by a processor, comprising:

• program instructions that arrange sequential portions of a data container into a plurality of regions on storage devices, each region including a predetermined amount of storage space represented by blocks on the storage devices;
• program instructions that organize the plurality of regions as active regions and other regions, each active region allocated for a different sequential portion of the data container and containing active file system data and snapshot data for the different sequential portion of the data container, wherein first blocks in a portion of the active region are marked as one of active for use in an active file system, active for use in one or more snapshots, and free;
• means for overwriting an active block within the active region with new active data if the active block is not required by the one or more snapshots;
• and
• means for preserving the active block to become a snapshot block of the data container and means for writing the new active data to any block marked as free in the active region if the active block is required by the one or more snapshots.