CLARiiON

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CLARiiON CX500
CLARiiON CX500

CLARiiON is a SAN disk array manufactured and sold by EMC Corporation. Occupying the entry-level and mid-range of EMC's SAN disk array product palette, it is complemented by the high-end Symmetrix.

The first CLARiiON was developed in the early 1990s by Data General Corporation, one of the first minicomputer companies. CLARiiON was an early commercial example of a RAID product and initially sold exclusively as an array with the company's AViiON line of computer systems. Realizing the enormous potential of storage arrays, Data General created a separate CLARiiON division and began selling the product as an OEM offering to its systems competitors. While this somewhat lessened the advantages of AViiON in the marketplace, and was a source of internal corporate friction, it allowed the company to sell higher volumes and popularize the brand. The strategy paid dividends as the company was acquired by EMC in 1999, primarily for the CLARiiON line of products.

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[edit] History

The CLARiiON disk array was started as a skunk works project inside Data General and was one of the first and most successful RAID product families introduced in the history of the computer industry. Ironically, shortly after the project's initial development, Tom West, the protagonist of the Pulitzer Prize winning book The Soul of a New Machine, usurped development of the product and led the company's last notable development effort prior to Data General's sale to EMC in 1999.

Patented in 1994, the CLARiiON disk array had some interesting features that are now standard in the data storage and computing industry. Features mentioned in the patent paperwork included optional hot swapping,[1] guide rails for proper electrical contact, and a method to lock the drives in place once they were secured in the disk enclosure. Other notable features include industry's first dual active controller design, mirrored write cache, full system redundancy and hot repair.[citation needed]

The CLARiiON line was soon extended to contain SCSI disk arrays ranging from 7 to 30 slots. In 1997, Data General's CLARiiON division took the unusual step of adopting an emerging standard - Fibre Channel. The FC5000 array utilized a Fibre Channel Arbitrated Loop connection that doubled the performance of SCSI arrays at that time. It was also the first to use RAID level 5 on Fibre Channel drives.[citation needed]

From there, the CLARiiON range grew into a faster, more expandable midrange storage platform, culminating in the FC5700 under Data General. After EMC's acquisition of Data General, significant development of a new range of CLARiiON arrays took place, resulting in the FC4500 and FC4700.

Within a couple of years, the first CX series of CLARiiONs (CX200, CX400 and CX600) was developed. Subsequent processor and bandwidth upgrades led to a new CX lineup (CX300, CX500, CX700) and a low end SATA based CLARiiON array, the AX100 (now updated to AX150). In 2003, CLARiiON became the industry's first NEBS-certified storage system.

In May 2006, EMC introduced the third generation of CLARiiON, named CX3 UltraScale. The lineup, consisting of the CX3-20, CX3-40 and CX3-80, was the industry's only storage platform to leverage end-to-end 4 Gbit/s (4 billion bits per second) Fibre Channel and PCI-Express technologies. Later in 2007, the line was expanded to include a new entry-level storage system, the CX3-10.

[edit] Current product lineup

[edit] AX series

The AX series is considered the entry-level disk array. It supports up to 12 Serial ATA disks with either 250, 500 or 750 GB (1 GB = 109 B) at a throughput of 150 (250 GB disks) or 300 MB/s (500, 750 GB disks) and, optionally, NCQ. Supported RAID levels are RAID 5 (with min. 3 disks) and RAID 1/0 (min. 4 disks).

Currently, the only model of the AX series is the AX150, which is available in four configurations which differ in connection and number of controllers.

Model Connection # of controllers
AX150 FC 2
AX150SC FC 1
AX150i iSCSI 2
AX150iSC iSCSI 1

The Fibre Channel connection supports transfer speeds of up to 2 Gbit/s (with both AL and SW configurations), iSCSI is physically limited to max. 1 Gbit/s.

[edit] CX series

The CX series supports both SATA and Fibre Channel disks. Supported RAID levels are 1/0, 0, 1, 3, 5, and 6; the disks can be configured into groups with different RAID levels.

Models of the CX series come in two configurations: Fibre Channel (transfer speeds max. 2 Gbit/s) and iSCSI (max. 1 Gbit/s). The exception is the CX700, which is FC only. The names of the iSCSI models end with an i, e.g. CX500i.

Model Max. FC hosts Max. disk drives Initial capacity Max. capacity (1 TB = 1012 B)
CX300 64 60 365 GB 27 TB
CX500 128 120 4 TB 59 TB
CX700 256 240 4 TB(?) 119 TB

[edit] CX3 UltraScale series

The CX3 UltraScale series contains multiple models which differ in the maximum number of disks (SATA or Fibre Channel) and the number of iSCSI and FC connections. The PCI Express connection between the FC interface and the storage processor allows transfer speeds of up to 4 Gbit/s, while iSCSI supports speeds of max. 1 Gbit/s. All current models support RAID 0, 1, 1/0, 3, 5, and 6; as with the CX series, groups with differing RAID levels can be created.

Each CX3 array consists of dual redundant hot-swappable components including storage processors, mirrored cache and battery backup, as well as dual power supplies. The CX3-10, CX3-20 and CX3-40 support both FC and iSCSI host connectivity, while the CX3-80 supports FC only.

Model Cache Front-end FC ports Front-end iSCSI ports Back-end ports Max. hosts Max. disk drives Max. capacity
CX3-10 2 GB 4 4 2 64 60 30 TB
CX3-20 4 GB 4 8 2 128 120 59 TB
CX3-40 8 GB 4/81 8/01 4 128 240 119 TB
CX3-80 16 GB 8 n/a 8 256 480 239 TB

1 The CX3-40 is available in two configurations, one purely FC and one combining FC and iSCSI.

[edit] External links

[edit] References

  1. ^ US5,371,743 (PDF version) (1994-12-06) DeYesso; Joseph P. (Walpole, MA), Solomon; Robert C. (Kensington, NH), Todd; Stephen J. (Shrewsbury, MA), Lippitt; Mark C. (Boulder, CO) On-line module replacement in a multiple module data processing system 
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