NVRAM caching and logging in a storage system

A system comprising:

• a first storage array having one or more solid state drives (SSDs);
• a first node connected to a non-volatile memory via a system bus, the first node attached to the first storage array,
• the first node configured to receive a plurality of input/output (I/O) requests each having a related data and a parameter,
• the first node further configured to acknowledge each of the plurality of I/O requests,
• the first node further configured to organize the related data of the plurality of I/O requests into a plurality of extents, by combining the related data of two or more first I/O requests of the plurality of I/O requests into a first extent, forming the related data of a second I/O request of the plurality of I/O requests into a second extent, and splitting the related data of a third I/O request of the plurality of I/O requests into two or more third extents,
• the first node further configured to store the plurality of extents in a cache in a first order, the cache stored in the non-volatile memory,
• the first node further configured to write the plurality of extents in a second order from the cache to the first storage array, wherein the second order differs from the first order,
• the first node further configured to receive a confirmation that each of the plurality of extents was successfully stored in the first storage array, and
• the first node further configured to delete the plurality of extents in the cache when each respective extent is confirmed to be successfully stored in the first storage array.

A system comprising:

• a first storage array having one or more solid state drives (SSDs);
• a first node having a non-volatile memory connected to a processor via a bus, the first node attached to the first storage array;
• and
• a storage I/O stack executing on the processor of the first node, the storage I/O stack when executed operable to:
• receive a plurality of input/output (I/O) requests each having a related data and a parameter,
• organize the related data of the plurality of I/O requests into units by combining the related data of two or more first I/O requests of the plurality of I/O requests into a single first unit, forming related data of a second I/O request of the plurality of I/O requests into a second unit, and splitting the related data of a third I/O request of the plurality of I/O requests into two or more third units,
• atomically store the plurality of units in the non-volatile memory in a first order,
• pass the plurality of units in a first path of the storage I/O stack to the first storage array for storage on the one or more SSDs in a second order, wherein the second order differs from the first order,
• pass the related parameters in a second path of the storage I/O stack, wherein the first path differs from the second path, for storage in a second storage array attached to a second node, and
• receive confirmation that each unit is stored on the one or more SSDs in the first storage array prior to marking the respective unit released in the non-volatile memory.