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1. What is RAIDZONE?
RAIDZONE is a family of products that implement a new approach to providing extremely high performance disk arrays at reasonable prices. At its heart, the RAIDZONE approach involves eliminating the traditional overhead of a peripheral bus, such as SCSI or FibreChannel, between the disk array and the computer's main PCI bus.
The RAIDZONE technology consists of a high performance PCI controller card, the SmartCan disk array enclosure, and the RAIDZONE Administration software package. The PCI RAIDZONE controller card extends the PCI bus directly to the SmartCan disk drive enclosures. Five high performance VLSI disk controllers on the SmartCan work in parallel, using high speed DMA to directly transfer data between the attached disks and the computer's main PCI bus. This enables the RAIDZONE controller/SmartCan combination to achieve extremely high aggregate throughput from multiple high speed disks. |
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2. What is a SmartCan?
The RAIDZONE SmartCan is a highly integrated disk enclosure that provides multi-disk controller electronics, mechanical disk mounting, electrical controls and cooling capabilities. Each SmartCan |
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assembly permits the mounting of five disk drives in the space of three standard half-height device slots. The SmartCan supports the hot swapping of disks, and includes five EasyGlide metal sliders to allow the easy installation and replacement of drives.
The SmartCan monitors and continuously reports a number of important disk array parameters including disk temperatures, disk input voltages (both +5 volt and +12 volt lines), and disk error status. The results can be viewed in the RAIDZONE Administration Program. The SmartCan also controls the pair of redundant PosiFlow fans mounted in its door, which provide reliable airflow to maintain optimal disk temperatures. |
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3. How big can you make a RAIDZONE disk array?
In a word, very big. Up to 4 SmartCans (20 disks) can be connected to a single RAIDZONE controller card, and multiple controller cards can be installed in a computer. Using 2 controller cards and 8 SmartCans in a system, and installing forty 12.5 GB drives, you could have a disk array with 500GB capacity -- that's half a terabyte! |
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4. How can you maximize RAIDZONE disk array performance?
Because RAIDZONE connects each disk in the array directly to the computer's PCI bus, the key to maximum performance is to use a computer with the fastest possible CPU, and an architecture that imposes the least possible system overhead on the PCI bus. For example, the latest Pentium II motherboards using the Intel 440LX chip set make three significant improvements --- (1) faster CPU; (2) separates the memory bus from the PCI bus, increasing effective PCI bus bandwidth; (3) uses the new AGP interface to keep graphics output off the PCI bus.
The ideal RAIDZONE disk array configuration would have a single RAIDZONE controller card on the PCI bus, and no other PCI cards in the system except perhaps a graphics card. Additional PCI cards, including a second RAIDZONE card, can create contention on the PCI bus and reduce throughput. |
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5. What operating systems work with RAIDZONE?
The RAIDZONE technology is available now for Windows NT Server and Windows NT Workstation. We expect to support Windows 98 and several versions of UNIX in the near future. |
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6. What RAID levels does RAIDZONE provide?
RAIDZONE provides the standard RAID levels 0 (striping), 1 (mirroring) and 5 (striping with parity). In addition, RAIDZONE provides a very useful type of high performance redundancy that we call ``RAID 10", a combination of mirroring and striping. For example, 10 disks could be mirrored in pairs to give five virtual disks, then those five virtual disks would be striped. This gives very high performance combined with complete redundancy. |
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7. Does RAIDZONE support hot swapping of disks, the use of a hot spare, and on-the-fly rebuilding?
Yes. RAID levels 1, 5, and 10 include redundancy that permits the disk array to continue operating in the face of a single disk failure. RAIDZONE allows you to designate one or more disks as ``hot spares", which can be immediately put into service to replace a failed disk. In addition, RAIDZONE's SmartCan allows you to ``hot swap" a failed disk for a replacement while the disk array continues operating. In either case, RAIDZONE can rebuild the replacement disk on-the-fly while continuing to service disk read and write requests from the operating system. |
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