I/O Write Request Handling in a Storage System

A system comprising:

• a processor;
• and
• a memory coupled to the processor, wherein the memory comprise instructions which, when executed by the processor, cause the processor to:
• receive an I/O write re nest created by an external device;
• create two parallel threads (T1, T2) for the write operation associated with the I/O write request:
• wherein the first thread (T1) attempts to execute a write operation associated with the I/O write request using the at least one normal storage device without using the at least one cache device, and
• wherein the second thread (T2) monitors the first thread (T1), and is triggered to execute the write operation associated with the I/O write request using the at least on cache device, if the first thread (T1) has not finished the write operation within a given time threshold (T(CacheActivate));
• provide an I/O write completion response to the external device in order to avoid timing out of the write operation;
• and
• free the at least one cache device from data written by the second thread (T2), if the first thread (T1) completes the write operation after the given time threshold (T(CacheActivate)).

A computer program product comprising a computer-readable storage medium having computer-readable program stored therein, wherein the computer-readable program, executed on a computing device, causes the computing device to:

• receive an I/O write request created by an external device;
• create two parallel threads (T1, T2) for the write operation associated with the I/O write request;
• wherein the first thread (T1) attempts to execute a write operation associated with the I/O write request using the at least one normal storage device without using the at least one cache device, and
• wherein the second thread (T2) monitors the first thread (T1), and is triggered to execute the write operation associated with the I/O write request using the at least on cache device, if the first thread (T1) has not finished the write operation within a given time threshold (T(CacheActivate));
• provide an I/O write completion response to the external device in order to avoid timing out of the write operation;
• and
• free the at east one cache device from data written by the second thread (T2), if the first thread (T1) completes the write operation after the given time threshold (T(CacheActivate)).