Example AP Configurations

Figure 1-9 shows how you can use AP to support an Ethernet network and a disk array.

Figure 1-9 Typical AP Configuration

In this example, two network controllers--one each on Board 1 and Board 2--are connected to the same network. Similarly, two SSA controllers on the two boards are connected to the same SSA. In this situation, if Board 1 is detached with a DR Detach operation, AP can switch usage to Board 2 without interfering with any I/O operations that may be in progress.

AP is not equivalent to disk mirroring. Disk mirroring achieves data redundancy. AP achieves pathing redundancy. Disk mirroring and AP are complementary; you can use them together to achieve both data redundancy and pathing redundancy. To do this, you must configure your volume manager software (Sun Enterprise Volume Manager or Veritas Volume Manager) so that is uses the AP metadisk paths.

Figure 1-10 AP and Disk Mirroring

This type of configuration enables you to switch the paths used to implement the mirror from one board to another board, without disrupting the disk mirroring or any active I/O.