Failover for failed secondary in cross-zone replicated block storage devices

A computer-implemented method to provide redundancy in a virtualized storage device replicated across at least a first and second zone of a plurality of zones, wherein the plurality of zones are in communication via a communication network but are isolated from one another, and wherein the virtualized storage device comprises a first volume in the first zone and a second volume in the second zone, the first volume configured to provide a first copy of data of the virtualized storage device and the second volume configured to provide a second copy of the data of the virtualized storage device, the computer-implemented method comprising:

• detecting a failure of the second volume of the virtualized storage device;
• selecting a zone from the plurality of zones in which to create a new volume for the virtualized storage device;
• generating the new volume within the selected zone, wherein the new volume is implemented by at least two computing devices within the selected zone, and wherein the new volume provides a third copy of the data of the virtualized storage device;
• causing the first volume to maintain a record of data in the first volume at a point in time;
• and
• causing the new volume to:
• replicate writes to the virtualized storage device obtained at the first volume subsequent to the point in time;
• and
• populate the new volume with the data in the first volume at the point in time using the record of data in the first volume at the point in time without overwriting replicated writes received subsequent to the point in time at least partly by copying, from the first volume to the new volume, data in the record that corresponds to locations of the first volume that have not been written to subsequent to the point in time without copying, from the first volume to the new volume, data in the record that corresponds to locations of the first volume that have been written to subsequent to the point in time.

A system to provide redundancy in a virtualized storage device replicated across at least a first and second zone of a plurality of zones, wherein the plurality of zones are in communication via a communication network but are isolated from one another, and wherein the virtualized storage device comprises a first volume in the first zone and a second volume in the second zone, the first volume configured to provide a first copy of data of the virtualized storage device and the second volume configured to provide a second copy of the data of the virtualized storage device, the system comprising:

• a data store including computer-executable instructions;
• and
• one or more processors configured to execute the computer-executable instructions to:
• select a zone from the plurality of zones in which to create a new volume for the virtualized storage device;
• generate the new volume within the selected zone, wherein the new volume is implemented by at least two computing devices within the selected zone, and wherein the new volume provides a third copy of the data of the virtualized storage device;
• cause the first volume to maintain a record of data in the first volume at a point in time;
• and
• cause the new volume to:
• replicate writes to the virtualized storage device obtained at the first volume subsequent to the point in time;
• and
• populate the new volume with the data in the first volume at the point in time using the record of data in the first volume at the point in time without overwriting replicas of the writes obtained at the first volume subsequent to the point in time at least partly by copying, from the first volume to the new volume, data in the record that corresponds to locations of the first volume that have not been written to subsequent to the point in time without copying, from the first volume to the new volume, data in the record that corresponds to locations of the first volume that have been written to subsequent to the point in time.