Know your SAN configuration
Understanding the SAN configuration is critical in SAN environments. Various SAN implementations have limitations or requirements on how the devices are configured and set up.
The three SAN configurations are point-to-point, arbitrated
loop, and switched fabric.
- Point-to-point
- The devices are connected directly to the host bus adapter (HBA).
- Arbitrated loop
- Arbitrated loop topologies are ring topologies and are limited in terms of the number of devices that are supported on the loop and the number of devices that can be in use at a given time. In an arbitrated loop, only two devices can communicate at the same time. Data being read from a device or written to a device is passed from one device on the loop to another until it reaches the target device. The main limiting factor in an arbitrated loop is that only two devices can be in use at a given time.
- Switched fabric
- In a switched fabric SAN, all devices in the fabric will be fibre native devices. This topology has the greatest bandwidth and flexibility because all devices are available to all HBAs through some fibre path.