Dell PowerConnect Brocade 815 Brocade Adapters Installation and Reference Manu - Page 49

Adapter features 1 • Interrupt Coalescing This feature provides a method to delay generation of host interrupts and thereby combine (coalesce) processing of multiple events. This reduces the interrupt processing rate and reduces the time that the CPU spends on context switching. You can configure the following parameters per port to adjust interrupt coalescing: - Interrupt time delay. There is a time delay during which the host generates interrupts. You can increase this delay time and thereby coalesce multiple interrupts events into one. This results in fewer interrupts for interrupt events. - Interrupt latency timer. An interrupt is generated when no new reply message requests occur after a specific time period. You can adjust this time period and thereby minimize I/O latency. • Internet Protocol over Fibre Channel (IPFC) driver This driver supports transmission of IP traffic over Fibre Channel links. It is only included in the Linux "noarch" RPM package (brocade_driver_linux_.tar.gz). • LUN masking. LUN masking establishes access control to shared storage to isolate traffic between different initiators that are zoned in with the same storage target. LUN masking is similar to zoning, where a device in a specific zone can communicate only with other devices connected to the fabric within the same zone. With LUN masking, an initiator port is allowed to only access those LUNs identified for a specific target. Enable LUN masking on an adapter physical port through the HCM Basic Port Configuration dialog box and the BCU fcpim -lunmaskadd command to identify the logical port (initiator) and remote WWN (target) for the LUN number. Refer to the Brocade Adapter Administrator's Guide for more information on configuration. This feature has following limitations. - Only 16 LUN masking entries are allowed per physical port - Multiple BCU instances for adding and deleting LUN masking are not supported - This feature is only supported on Brocade HBAs and Fabric Adapters. You can configure LUN masking for a particular target even without the actual devices being present in the network. When configuring boot over SAN, mask the boot LUN so that the initiator has exclusive access to the boot LUN. Refer to the Brocade Administrator's Guide for more information. • N_Port ID Virtualization (NPIV). This allows multiple N_Ports to share a single physical N_Port. This allows multiple Fibre Channel initiators to occupy a single physical port and reduce SAN hardware requirements. • Simple Network Management Protocol (SNMP) SNMP is an industry-standard method of monitoring and managing network devices. Brocade CNA adapters and Fabric Adapter ports configured in CNA mode provide agent and MIB support for SNMP. For more information, refer to "Simple Network Management Protocol" on page 34. • Target rate limiting. You can enable or disable this feature on specific ports. Target Rate Limiting relies on the storage driver to determine the speed capability of a discovered remote ports, then uses this information to throttle FCP traffic rate to slow-draining targets. This reduces or eliminates network congestion and alleviates I/O slowdowns at faster targets. Brocade Adapters Installation and Reference Manual 21 53-1002144-01