Methods, systems and computer products for user-managed multi-path performance in balanced or unbalanced fabric configurations

A path priority selection method, comprising:

• assigning a medium priority to paths in a storage area network, wherein the medium priority is between a highest priority and a lowest priority;
• selecting at least one of a high and a low priority for the paths in the storage area network;
• directing a load I/O balance of the storage area network to a path having the high priority;
• and
• selecting a path for an I/O load based on a path selection algorithm when more than one path has the high priority, the path selection algorithm including at least one of load-balancing and round-robin,
• wherein if there is only one path of the one or more paths having the high priority, all I/O traffic is biased to the only one high priority path,
• 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.

A computer program product including a non-transitory computer readable medium storing instructions for causing a computer to implement a path priority selection method, the 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.

A path priority selection system, comprising:

• a storage device;
• a plurality of adapters;
• a plurality of paths disposed between and communicatively coupling the storage device and the plurality of adapters, the plurality of paths having a default medium priority, wherein the default medium priority is between a highest priority and a lowest priority;
• and
• a device driver configured to:
• set a path priority among the plurality of paths, the path priority including at least one of a low priority and a high priority;
• direct all I/O traffic among a first I/O data path of the plurality of paths, and a second I/O data path of the plurality of paths;
• select the first I/O data path to be a highest priority path in, wherein all I/O traffic is biased to the highest priority path;
• select 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;
• select an I/O threshold value, the I/O threshold value indicating that an I/O data load is excessive;
• direct 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;
• monitor the first I/O data path;
• determine if the first I/O data path has reached the threshold value;
• and
• perform 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.