HP StorageWorks 8/80 HP StorageWorks Fabric OS 6.1.x administrator guide (5697 - Page 381

• IPSec can only be configured on IP V4 based tunnels. Secure tunnels can not be created on a 400 Multi-protocol Router or FR4-18i blade if any IP V6 addresses are defined on either ge0 or ge1. • Secure Tunnels cannot be defined with VLAN Tagged connections. Options for enhancing tape write I/O performance There are two options available for enhancing open systems SCSI tape write I/O performance. • FCIP fastwrite and tape pipelining. • FC fastwrite. FCIP fastwrite and tape pipelining are implemented together. FC fastwrite is an FC-FC routing alternative that disables the local Ethernet ports (ge0 and ge1), making it impossible to configure FCIP fastwrite and tape pipelining and FC fastwrite on the same 400 Multi-protocol Router or FR4-18i blade. Refer to "FC fastwrite concepts" on page 461 for information about FC fastwrite. FC fastwrite flows may be routed to another 400 Multi-protocol Router or FR4-18i blade on the FC network. This 400 Multi-protocol Router or FR4-18i blade may have active FCIP tunnels over an IP network. FC fastwrite flows may be passed through the FCIP tunnel, but only if the FCIP fastwrite option is disabled on the tunnel. FCIP fastwrite and tape pipelining When the FCIP link is the slowest part of the network, consider using FCIP fastwrite and tape write tape pipelining. Supported only in Fabric OS 5.2.x and later, FCIP fastwrite and tape pipelining are two features that provide accelerated speeds for write I/O over FCIP tunnels in some configurations: • FCIP fastwrite accelerates the SCSI write I/Os over FCIP. • Tape pipelining accelerates SCSI write I/Os to sequential devices (such as tape drives) over FCIP, which reduces the number of round-trip times needed to complete the I/O over the IP network and speeds up the process. To use tape pipelining, you must also enable fastwrite. • Both sides of an FCIP tunnel must have matching configurations for these features to work. FCIP fastwrite and tape pipelining are enabled by turning them on during the tunnel configuration process. They are enabled on a per-FCIP tunnel basis. See"Configuring FCIP tunnels" on page 394 for details. Constraints for FCIP fastwrite and tape pipelining Consider the constraints described in Table 88 when configuring tunnels to use either of these features. Table 88 Using FCIP fastwrite and tape pipelining FCIP fastwrite Tape pipelining Each GbE port supports up to 2048 simultaneous accelerated exchanges, which means a total of 2048 simultaneous exchanges combined for fastwrite and tape pipelining. Does not affect FICON traffic Each GbE port supports up to 2048 simultaneous accelerated exchanges, which means a total of 2048 simultaneous exchanges combined for fastwrite and tape pipelining. Does not affect FICON traffic FCIP fastwrite and FC fastwrite are mutually exclusive. Tape pipelining uses FCIP fastwrite, not FC fastwrite. Does not support multiple equal-cost path configurations (see "FCIP fastwrite/tape pipelining configurations" on page 382). Does not support multiple equal-cost path configurations or multiple non-equal-cost path configurations (see "FCIP fastwrite/tape pipelining configurations" on page 382). Fabric OS 6.1.x administrator guide 381