HP LH4r Pre-Failure Warranty-Minimizing Unplanned Downtime - Page 6

ZKLWHýSDSHU +3ý 1HW6HUYHUý 0DQDJHPHQW commonplace in DRAM cells, cause data to be stored incorrectly in a memory location, but subsequent accesses can correctly store data into that cell. With properly tuned hardware and software, occurrences of soft errors should be months or possibly years apart. In reality, the environment and other hardware and software conflicts can cause noise or contention that may precipitate more frequent random memory errors. To protect the server from data loss associated with these errors, HP offers ECC memory scrubbing as a diagnostic and repair tool. Basic ECC memory detects and corrects singlebit memory errors, however, the errors themselves still remain in RAM. Each time the bad data bit is accessed, it must be re-corrected by the memory controller. Two versions of memory scrubbing are available-proactive and reactive. Reactive memory scrubbing improves on basic ECC memory by writing the corrected data to RAM, after the error occurs. Proactive memory scrubbing scrubs memory at pre-scheduled times or upon demand. In either case, when a memory error is detected, the corrected data is written back to RAM. This action ensures that all ECC memory errors will be logged and the bad data bits are "scrubbed" from RAM. The Pre-Failure Warranty covers the replacement of Single In-Line or Dual In-Line Memory Modules (SIMMs or DIMMs) used in the server's main memory when the predefined thresholds for correctable (soft) errors have been exceeded. Soft errors are recorded in the Event log and a pre-failure alert is issued through HP TopTools for Servers. Third-Party Memory HP recognizes that purchasing or upgrading a mission-critical server requires confidence that the server possesses high-quality memory compatible with the other components and subsystems, so HP subjects its memory modules to a tough testing and qualification process. HP quality and compatibility testing identifies the most reliable memory for use in each HP NetServer. HP is confident of the quality and testing performed on its components; therefore, the company warrants all products manufactured or distributed by HP. HP warranties do not cover third-party memory, nor the damage that third-party memory might cause. Power Subsystem and Voltage Regulator Module An uninterruptible power supply (UPS) is the most cost-effective step in increasing overall system availability. Once you have protected and conditioned the power reaching the system itself, the next component to consider is the power supply. Because power supplies have a lower meantime between failure (MTBF) than digital electronic circuits, it is a good idea to have redundancy built into the system. HP NetServers have redundant power supplies included throughout the L Series. The HP Pre-Failure Warranty for the power supplies provides an additional measure of protection. The HP NetServer monitors the power supply voltages (+5v, +12v, -12v and 3.3v). Additionally, since a Voltage Regulator Modulator (VRM) powers each processor in a HP NetServer, the system also monitors the voltage of each VRM. 6