What is Multi-pathing?
Put in its simplest form, Multi-pathing means connecting a RAID to a server using two data cables. Path redundancy allows continuous access to data in the event of single cable or HBA failure. The problem is, a RAID array may appear as two separate devices to the server OS. Therefore, a Multi-pathing software, such as Infortrend’s EonPath, becomes necessary by managing the access and telling host OS that these are alternate paths to a single device. In the event of cable disconnection or failure, the software can help direct I/Os through the existing connection. Since I/Os can be distributed across multiple data paths, an intelligent Multi-pathing software is also capable of load-balancing policies such as round-robin, least weight, etc., and thereby making the optimal use of path bandwidth.
