User manual HP COMPAQ STORAGEWORKS 4000 RAID ARRAY COMPAQ RAID ARRAY 4000 OVERVIEW

[. . . ] Technology Brief June 1999 ECG0205699A Prepared by ECG Technology Communications Group Compaq Computer Corporation Compaq RAID Array 4000 Overview Abstract: The Compaq StorageWorks RAID Array 4000 (RA4000), formerly the Fibre Channel Storage System, is an external storage solution incorporating Fibre Channel interconnect technology. This solution overcomes inherent limitations of small computer systems interface (SCSI) interconnect technology. Fibre Channel interconnect technology is designed to satisfy the requirements of such enterprise applications as databases, data marts, email, groupware, Web servers, and file and print for large storage capacity and scalable input/output (I/O) performance. The architecture of this Fibre Channel storage solution enables administrators to simultaneously achieve multiple goals: · · To provide hardware redundancy and failover capabilities with no single point of failure (NSPOF). [. . . ] Cleaning should be performed any time that an open connection might have been exposed to dust or that there is doubt about the connector's cleanliness. A cleaning kit is available from Compaq for this purpose. ECG0205699A Compaq RAID Array 4000 Overview 12 Cables The RA4000 uses 50-micron, multi-mode fiber optic cable, and 9-micron, single-mode fiber optic cable. The RA4000 ships with a 2-meter multi-mode cable. The Fibre Channel Host Adapter ships with a 5-meter multi-mode cable. Standard lengths for multi-mode cable option kits are 2 meter, 5 meter, 15 meter, 30 meter, and 50 meter. For installations requiring longer cable lengths, single-mode cables, or additional cables, customers may contact a Compaq reseller or special cable supplier. Refer to www. compaq. com and www. networks. digital. com/dr/opendec for more detailed information on Fibre Channel transmission, types of cable, and connection components. Figure 6. Fiber optic cable Hardware Architecture Fibre Channel is the best interconnect technology to overcome inherent I/O and physical limitations of SCSI technology and to propel future growth of enterprise storage. For its first scalable Fibre Channel storage solution for x86-based servers, Compaq selected FC-AL topology. An FC-AL is a serial interface that creates logical point-to-point connections between ports. Because it uses the minimum number of transceivers and no centralized switching function, FC-AL provides a low-cost, yet highly flexible solution. Each Fibre Channel node has one or more ports that enable external communication. Each port uses two fibers to communicate with its neighboring ports on the loop, one for incoming information and the other for outgoing information. All of the components that connect ports comprise the interconnect topology. ECG0205699A Compaq RAID Array 4000 Overview 13 Figure 7 shows that the Storage Hub 7 contains seven serially connected ports. The Storage Hub 12, on the other hand, contains 12 serially connected ports. Internal signaling within the hubs is electrical. The internal hub connections and logic create an FC-AL. The bandwidth of the loop is shared by all ports on the loop. A single pair of ports on the loop communicates at any one time, while the other ports on the loop act as repeaters. Each port is fitted with a port bypass switch to maintain the continuity of the loop in the event a controller or device attached to that port malfunctions or is powered off. This port bypass capability improves fault tolerance. Figure 7. Compaq StorageWorks Fibre Channel Storage Hub 7 The shortwave laser technology used in the RA4000 supports transmission distances between components of up to 500 meters on 50-micron, multi-mode fiber optic cable with no electromagnetic interference. [. . . ] Refer to www. compaq. com for details about migrating to an RA4000 from a Compaq ProLiant Storage system using the Compaq SMART Array controllers. ECG0205699A Compaq RAID Array 4000 Overview 22 Clustering with RA4000 A cluster is a loosely coupled collection of servers and storage devices that are managed by cluster management software. Clustering provides high availability of applications and data and performance scalability. Clustering with RA4000 systems benefits business-critical application because RA4000 technology ensures that applications stay up and running through: · · · Redundant components in storage. Software that provides failover of hardware. Clustered RA4000s provide investment protection and flexibility in certain configurations. [. . . ]