Storage systems with adaptive erasure code generation

A method for storing data, comprising:

• copying and storing a first data block, by a storage system, to a first, a second, and a third computer-storage node of the storage system;
• copying and storing a second data block, by the storage system, to the first, a fourth, and a fifth computer-storage node of the storage system;
• copying and storing a third data block, by the storage system, to the first, the third, and the fourth computer-storage node of the storage system;
• generating and storing, by the storage system, a first and a second parity of the first, the second, and the third data block on the first computer-storage node;
• transferring the second parity to be stored away from the first computer-storage node, leaving only the first parity stored on the first computer-storage node;
• and
• discarding extra copies of the first, second and third data block, such that there is only one copy of each of the first, second and third data block stored among the first, second, third, fourth and fifth computer-storage node;
• wherein each of the first, second and third data blocks is recoverable from any three of the first and second parities, and the first, second and third data blocks selectively stored in the first, second, third, fourth and fifth computer-storage node.

One or more computer-readable storage media having a plurality of instructions to cause a storage system, in response to execution of the instructions by the storage system, to:

• copy and store a first data block to a first, a second, and a third of a plurality of computer-storage nodes of the storage system;
• copy and store a second data block to the first, a fourth, and a fifth of the computer-storage nodes;
• copy and store a third data block to the first, the third, and the fourth computer-storage nodes;
• generate and store a first and a second parity of the first, second, and third data block on the first computer-storage node;
• transfer the second parity to be stored away from the first computer-storage node, leaving only the first parity stored on the first computer-storage node;
• and
• discard extra copies of the first, second and third data block, such that there is only one copy of each of the first, second and third data block stored among the first, second, third, fourth and fifth computer-storage node;
• wherein each of the first, second and third data blocks is recoverable from any three of the first and second parities, and the first, second and third data blocks selectively stored in the first, second, third, fourth and fifth computer-storage node.