Patent ID: 8250256

Claim:
A path priority selection method, comprising: directing, in a storage area network system, all I/O traffic among a first I/O data path, and a second I/O data path, both the first and second I/O data paths have a default medium priority, wherein the default medium priority is between a highest priority and a lowest priority; selecting the first I/O data path to be a highest priority path, wherein all I/O traffic is biased to the highest priority path; selecting the second I/O data path to be a low priority path, in which no I/O traffic is directed with an availability of the highest priority path to receive all of the I/O traffic; selecting an I/O threshold value, the I/O threshold value indicating that I/O data load is excessive; directing the load balance of I/O traffic to the first I/O data path, thereby placing the second I/O data path in a standby state; monitoring the first I/O data path; determining if the first I/O data path has reached the threshold value; and performing a controlled failover of the first I/O data path to the second I/O data path when an I/O data load on the first data path has reached the threshold value, wherein the first I/O data path has a faster speed than the second I/O data path, and wherein the second I/O data path remains online when the second I/O data path does not have any I/O traffic directed to it.