File system image transfer

A file system having a plurality of storage blocks, said file system including a snapshot including a set of member storage blocks selected from said plurality, said member storage blocks forming a consistent file system other than an active file system;

• said snapshot being disposed as an object in said file system, wherein said file system is responsive to at least one file system request with regard to said snapshot.

A method to be performed in a file system, said file system having a plurality of storage blocks, said method including steps for

• defining a storage image of a set of member storage blocks selected from said plurality, said storage image being formed in response to a set of member storage blocks forming a consistent file system other than an active file system;
• and
• forming an image stream of a sequence of member storage blocks selected from said storage image.

An incremental mirror copy of a file system, said incremental copy including a base set of storage blocks stored in a first storage medium, and an incremental set of storage blocks stored in a second storage medium.

Apparatus including

• a file system including a plurality of snapshots thereof, each representing an associated consistent state at an associated selected time;
• and
• each said snapshot including an indication of a set of storage blocks in said associated consistent state, said indication being recorded in at least one storage block in said associated consistent state.

In a file system having a plurality of storage blocks, a data structure including

• a first snapshot of a set of member storage blocks selected from said plurality, said member storage blocks forming a consistent file system other than an active file system;
• said first snapshot being represented as an object in said file system and having a set of storage blocks for recording said first snapshot;
• whereby copying said member storage blocks in said first snapshot has the property of preserving at least one snapshot recorded in said file system at a time of said first snapshot.

In a file system having a plurality of storage blocks, a data structure including

• a snapshot of a set of member storage blocks selected from said plurality, said member storage blocks forming a consistent file system other than an active file system;
• said snapshot being represented as an object in said file system and having a set of storage blocks for recording said snapshot;
• whereby a backup and restore operation on said file system has the property of preserving said snapshot within said file system.

In a file system having a plurality of storage blocks, a data structure including

• a storage image of a set of member storage blocks selected from said plurality;
• said storage image being formed in response to a set of member storage blocks forming a consistent file system other than an active file system.

In a file system having a plurality of storage blocks, a data structure including a shadow snapshot of a set of member storage blocks selected from said plurality, said member storage blocks having formed a consistent file system other than an active file system, with a set of selected member storage blocks removed from said consistent file system.

In a file system having a plurality of storage blocks, a data structure including a mark-on-allocate image of a set of member storage blocks selected from said plurality, said member storage blocks having been added to a snapshot that originally formed a consistent file system.

In a file system having a plurality of storage blocks, a data structure including a mark-on-deallocate image of a set of member storage blocks selected from said plurality, said member storage blocks having been removed from a snapshot that originally formed a consistent file system.