Patent attributes
Capturing post-snapshot quiescence writes in a branching image backup chain. In one example embodiment, a method for capturing post-snapshot quiescence writes in a branching image backup chain may include taking a first snapshot of a source storage at a first point in time, identifying a first set of block positions of blocks that are allocated in the source storage at the first point in time, identifying a second set of block positions of blocks that are written to the first snapshot during post-snapshot quiescence of the first snapshot, resulting in a first quiesced snapshot, copying the blocks in the first set of block positions from the first snapshot to a full image backup, copying the blocks in the second set of block positions from the first quiesced snapshot to a first incremental image backup that depends on the full image backup, tracking a third set of block positions of the blocks that are modified in the source storage between the first point in time and a second point in time, taking a second snapshot of the source storage at the second point in time, identifying a fourth set of block positions of the blocks that are allocated in the source storage at the second point in time, identifying a fifth set of block positions of blocks that are written to the second snapshot during post-snapshot quiescence of the second snapshot, resulting in a second quiesced snapshot, calculating a sixth set of block positions by performing a Boolean AND operation on the third set of block positions and the fourth set of block positions, copying the blocks in the sixth set of block positions from the second snapshot to a second incremental image backup that depends on the full image backup, and copying the blocks in the fifth set of block positions from the second quiesced snapshot to a third incremental image backup that depends on the second incremental image backup.