Separating disk and tape communication via separate HBAs in a host is a great way to ensure best possible disk performance, minimize tape interaction affecting disk writes and ease management for troublebshooting. In a Compaq SecurePath environment, it is important to recall that the KGPSA-CB HBAs used by Compaq to complete SecurePath are rebranded Emulex HBAs. Using a separate FC HBA in an NT server, it is critical to use any HBA other than Emulex as SecurePath, or the OS will not allow the tape area network (TAN) HBA drivers to be upgraded for persistent binding. This is not an issue for Win2K. Additionally, Emulex specifically advises against integrating more than two Emulex FC HBAs in a NT 4 server.
About the author: Robert Brower is the director of engineering and project management for Adexis, a division of Cranel, Inc. that is focused solely on storage, recovery and high availability solutions.