HP DL360 ProLiant High Availability: The IT Imperative - Page 3

SPECIAL ADVERTISING SECTION figure 2. fast path failover FAILURE: team's primary NIC has 100 Mbps path to core switch NIC 1 primary SWITCH A ▼ Gigabit Ethernet 100 Mbps ▼ secondary NIC 2 SWITCH B HP ProLiant server CORE SWITCH slower cross-link RECOVERY: team's new primary NIC has gigabit path to core switch NIC 1 new primary new secondary NIC 2 SWITCH A ▼ Gigabit Ethernet 100 Mbps ▼ SWITCH B HP ProLiant server CORE SWITCH monitor for connectivity to the core network. The primary path automatically fails over to the secondary path as soon as it senses a loss of connectivity. Fast path failover determines the fastest path to the core switch to help maximize network performance and availability by identifying network path degradation. For example, fast path failover would detect if the Gigabit Ethernet connection from an access switch to a core switch fails and the traffic is re- routed over a 100-Mbps Ethernet connection. It would then fail the traffic over to an alternative Gigabit Ethernet connection. Dual channel teaming allows system administrators to create a team of NICs that support receive and transmit load balancing, and provides switch redundancy. This combination of capabilities is not available with any other basic team types such as switch-assisted load balancing (SLB) or transmit load balancing (TLB). With dual channel teaming, two NIC teams appear as a single connection to the server. If one of the switches fails, there is no loss of connectivity and the failed switch can be replaced without affecting server traffic. Virus throttle can slow down the spread of virus, leaving time for IT intervention before the entire network becomes infected. Traditional approaches to anti-viral protection are based on the actual code or signature of the virus. Virus throttle identifies viruses on the basis of their behavior. Because it works without knowing anything about the virus, it can handle unknown virus without waiting for signature updates. virtual presence HP's Integrated Lights-out (iLO) technology reduces cost and increases server availability by giving an IT organization a virtual presence within the data center as well as on any remote system. That means no matter where the server is located, the IT organization has control over the key system resources such as the console, keyboard, mouse and power. Using iLO, an IT organization even has the ability to make storage media appear local to the server. In addition, iLO continues to operate even if the server's operating system is not functioning. IT organizations can use iLO to install, configure, monitor, update and troubleshoot remote ProLiant servers from a standard web browser, command line or script without requiring any additional software on the client system. iLO is integrated with other management tools, making it easier to combine virtual presence capabilities with other server lifecycle management tasks from deployment to ongoing administration. memory protection technologies ProLiant servers use a variety of techniques to protect against errors, and hence increase availability. For example, HP was one of the first companies to introduce advanced memory protection technology such as ECC (Error-Correcting Code) memory, online spare memory, mirrored memory and RAID memory in industrystandard servers. To improve memory protection even further, HP introduced Advanced ECC technology. Advanced ECC technology is capable of correcting a multi-bit error that occurs within one dynamic random access memory (DRAM) chip. The ProLiant server online spare memory determines if an active DIMM (dual inline memory module) exceeds a predefined error threshold. The error will be corrected and the data from the entire bank that contains the failed DIMM will be copied to online spare memory. The failed bank is deactivated, but the server will remain available until the failed DIMM is replaced during a scheduled shutdown. Whereas online spare memory mode protects against single-bit errors and entire DRAM failure, mirrored memory mode enables full protection against single-bit and multi-bit errors. In mirrored memory mode, the same data is written to both system memory and mirrored memory banks, but data is read only from the system memory banks. If a DIMM in the system memory banks experiences a multi-bit error or reaches the pre-defined error threshold for single-bit errors, the roles of the system and mirrored memory banks are reversed. HP is one of the first companies to support hot plug RAID memory, which allows the memory subsystem to operate continuously even in the event of a complete memory device failure. In this context, RAID stands for Redundant Array of Industry-standard DIMMs. Hot plug RAID memory generates parity for an entire cache line of data during write operations and records the parity information on a dedicated parity cartridge. However, hot plug RAID memory does not have the mechanical delays of seek time, rotational latency and bottlenecks associated with disk drive arrays. 3a