CLARiiON
Encyclopedia
Storage area network
A storage area network is a dedicated network that provides access to consolidated, block level data storage. SANs are primarily used to make storage devices, such as disk arrays, tape libraries, and optical jukeboxes, accessible to servers so that the devices appear like locally attached devices...
disk array
Disk array
A disk array is a disk storage system which contains multiple disk drives. It is differentiated from a disk enclosure, in that an array has cache memory and advanced functionality, like RAID and virtualization.Components of a typical disk array include:...
manufactured and sold by EMC Corporation
EMC Corporation
EMC Corporation , a Financial Times Global 500, Fortune 500 and S&P 500 company, develops, delivers and supports information infrastructure and virtual infrastructure hardware, software, and services. EMC is headquartered in Hopkinton, Massachusetts, USA.Former Intel executive Richard Egan and his...
, it occupies the entry-level and mid-range of EMC's SAN disk array products.
Upon launch in 2008, the latest generation CX4 series storage arrays support fibre channel
Fibre Channel
Fibre Channel, or FC, is a gigabit-speed network technology primarily used for storage networking. Fibre Channel is standardized in the T11 Technical Committee of the InterNational Committee for Information Technology Standards , an American National Standards Institute –accredited standards...
and iSCSI
ISCSI
In computing, iSCSI , is an abbreviation of Internet Small Computer System Interface, an Internet Protocol -based storage networking standard for linking data storage facilities. By carrying SCSI commands over IP networks, iSCSI is used to facilitate data transfers over intranets and to manage...
front end bus connectivity. The fibre channel back end bus offers 4 Gbit/s of bandwidth with FC-SCSI disks or SATAII disks.
The EMC Celerra
Celerra
Celerra is a discontinued NAS device produced by EMC Corporation. It was available as an integrated unit or as a NAS header which can be added to an independent EMC storage array such as a CLARiiON or a Symmetrix. It supports CIFS, NFS, FTP, NDMP, TFTP and MPFS protocols...
NAS device is based on the same X-blade architecture as the CLARiiON storage processor.
The first CLARiiON was developed in 1992 by Data General
Data General
Data General was one of the first minicomputer firms from the late 1960s. Three of the four founders were former employees of Digital Equipment Corporation. Their first product, the Data General Nova, was a 16-bit minicomputer...
Corporation, one of the first minicomputer companies. CLARiiON was an early commercial example of a RAID
RAID
RAID is a storage technology that combines multiple disk drive components into a logical unit...
product and initially sold exclusively as an array with the company's AViiON
Data General AViiON
AViiON was a series of computers from Data General that were the company's main product from the late 1980s until the company's server products were discontinued in 2001. Earlier AViiON models used the Motorola 88000 CPU, but later models moved to an all-Intel solution when Motorola stopped work on...
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
Original Equipment Manufacturer
An original equipment manufacturer, or OEM, manufactures products or components that are purchased by a company and retailed under that purchasing company's brand name. OEM refers to the company that originally manufactured the product. When referring to automotive parts, OEM designates a...
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.
As of 2011 the Clariion and Celerra products have been replaced by the new VNX series of unified storage disk arrays. Internally the VNX is labeled the CX5.
History
The CLARiiON disk array project started in the early 1990s when Tom WestTom West
Joseph Thomas "Tom" West III was the protagonist of the Pulitzer Prize winning non-fiction book The Soul of a New Machine. West worked for Data General Corporation as a hardware engineer and vice president, retiring as Chief Technologist in 1998. West died at the age of 71 in his Westport,...
(the protagonist of the Pulitzer Prize winning book The Soul of a New Machine
The Soul of a New Machine
Tracy Kidder's non-fiction book, The Soul of a New Machine, chronicles the experiences of an engineering team racing to design a next generation computer under a blistering schedule and tremendous pressure. This machine was eventually launched in 1980 as the Data General Eclipse MV/8000...
) convinced Data General to develop the array. West realized the potential for more advanced and openly compatible data-storage devices, as did competitors such as Digital Equipment Corporation with their StorageWorks
HP StorageWorks
In computing, HP Storage , a portfolio of Hewlett-Packard storage products, includes online storage, nearline storage, storage networking, archiving, de-duplication, and storage software. HP has developed many industry-first storage technologies to simplify network storage...
product.
Patented in 1994, the CLARiiON disk array had some interesting features that later became standard in the data-storage and computing industry. Features mentioned in the patent paperwork included optional hot swapping
Hot swapping
Hot swapping and hot plugging are terms used to describe the functions of replacing computer system components without shutting down the system...
, 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.
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
Fibre Channel
Fibre Channel, or FC, is a gigabit-speed network technology primarily used for storage networking. Fibre Channel is standardized in the T11 Technical Committee of the InterNational Committee for Information Technology Standards , an American National Standards Institute –accredited standards...
. 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
RAID
RAID is a storage technology that combines multiple disk drive components into a logical unit...
level 5 on Fibre Channel drives.
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
Gigabit
The gigabit is a multiple of the unit bit for digital information or computer storage. The prefix giga is defined in the International System of Units as a multiplier of 109 , and therefore...
/s (4 billion bit
Bit
A bit is the basic unit of information in computing and telecommunications; it is the amount of information stored by a digital device or other physical system that exists in one of two possible distinct states...
s 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.
Most newer CLARiiON models run a version of Windows XP Embedded.
Architecture
The CLARiiON is built on an Intel platform with embedded Windows (in the fourth generation this is 64-bit Windows Storage Server, the third generation used 32-bit Windows XP). The form factor is a half-width 1U or 2U device known as an X-blade, two of which are mounted side by side in the storage processor enclosure. This provides a fully redundant active-active configuration, with both storage processors serving requests and each acting as failover for the other so that initiators see the array as active-passive. An integrated UPSUninterruptible power supply
An uninterruptible power supply, also uninterruptible power source, UPS or battery/flywheel backup, is an electrical apparatus that provides emergency power to a load when the input power source, typically mains power, fails...
provides security for data in the event of power failure.
Storage is fibre attached, initiators may be fibre or IP attached, the architecture supports both on the same array depending on configuration. Storage is connected via back-end loops with up to 120 drives per loop, the drives are contained in Disk Array Enclosures (DAEs) of 15 drives each.
The operating environment, FLARE (Fibre Logic Array Runtime Environment), resides on the first five disks of the first DAE (bus 0 enclosure 0), which is also supplied by the integrated UPS. In the event of power failure this space is also used to store the contents of the write cache so that all writes are completed on restoration of power.
Management of the CLARiiON is usually through inbuilt Java-based management software called Navisphere.
With the fourth generation UltraFlex series, IO is provided through pluggable modules providing either IP or fibre connectivity, allowing additional back end and front end connections to be added over the life of the array.
Advanced functionality of the CLARiiON is licensed and enabled through software. This includes SAN replication, Quality of service
Quality of service
The quality of service refers to several related aspects of telephony and computer networks that allow the transport of traffic with special requirements...
(QOS) and snapshots
Snapshot (computer storage)
In computer systems, a snapshot is the state of a system at a particular point in time. The term was coined as an analogy to that in photography. It can refer to an actual copy of the state of a system or to a capability provided by certain systems....
.
AX series
The AX series is considered the entry-level disk array.Currently, two models are available the AX4 and the AX150.
The AX150 supports up to 12 Serial ATA
Serial ATA
Serial ATA is a computer bus interface for connecting host bus adapters to mass storage devices such as hard disk drives and optical drives...
disks with either 250, 500 or 750 GB
Gigabyte
The gigabyte is a multiple of the unit byte for digital information storage. The prefix giga means 109 in the International System of Units , therefore 1 gigabyte is...
(1 GB = 109 B
Byte
The byte is a unit of digital information in computing and telecommunications that most commonly consists of eight bits. Historically, a byte was the number of bits used to encode a single character of text in a computer and for this reason it is the basic addressable element in many computer...
) at a throughput of 150 (250 GB disks) or 300 MB/s (500, 750 GB disks) and, optionally, NCQ
Native Command Queuing
Native Command Queuing is a technology designed to increase performance of SATA hard disks under certain conditions by allowing the individual hard disk to internally optimize the order in which received read and write commands are executed...
. Supported RAID
RAID
RAID is a storage technology that combines multiple disk drive components into a logical unit...
levels are RAID 5 (with min. 3 disks) and RAID 1/0 (min. 4 disks). The Fibre Channel connection supports transfer speeds of up to 2 Gbit/s (with both AL
Arbitrated loop
Arbitrated loop, also known as FC-AL, is a Fibre Channel topology in which devices are connected in a one-way loop fashion in a ring topology. Historically it was a lower-cost alternative to a fabric topology. It allowed connection of many servers and computer storage devices without using then...
and SW
Switched fabric
Switched fabric, switching fabric, or just fabric, is a network topology where network nodes connect with each other via one or more network switches . The term is popular in telecommunication, Fibre Channel storage area networks and other high-speed networks, including InfiniBand...
configurations), iSCSI is physically limited to max. 1 Gbit/s. The AX150 is available in four configurations which differ in connection and number of controllers.
The AX4 is the successor of the AX150 and can support up to 60 Serial ATA
Serial ATA
Serial ATA is a computer bus interface for connecting host bus adapters to mass storage devices such as hard disk drives and optical drives...
or Serial Attached SCSI
Serial Attached SCSI
Serial Attached SCSI is a computer bus used to move data to and from computer storage devices such as hard drives and tape drives. SAS depends on a point-to-point serial protocol that replaces the parallel SCSI bus technology that first appeared in the mid 1980s in data centers and workstations,...
disks (with "Expansion Pack"). The base version has only place for 12 disks. Similar to the AX150 it is available in iSCSI or Fibre Channel configurations. Opposed to the AX150 the AX4 supports Fibre Channel transfer speeds of up to 4 Gbit/s.
| Model | Connection | # of controllers | speed | # of supported disks |
|---|---|---|---|---|
| AX150 | FC | 2 | 2 Gbit/s | 12 |
| AX150SC | FC | 1 | 2 Gbit/s | 12 |
| AX150i | iSCSI | 2 | 1 Gbit/s | 12 |
| AX150iSC | iSCSI | 1 | 1 Gbit/s | 12 |
| AX4-5F | FC | 1 or 2 | 4 Gbit/s | 12 (60 with "Expansion Pack") |
| AX4-5I | iSCSI | 1 or 2 | 1 Gbit/s | 12 (60 with "Expansion Pack") |
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 Terabyte The terabyte is a multiple of the unit byte for digital information. The prefix tera means 1012 in the International System of Units , and therefore 1 terabyte is , or 1 trillion bytes, or 1000 gigabytes. 1 terabyte in binary prefixes is 0.9095 tebibytes, or 931.32 gibibytes... |
| CX500 | 128 | 120 | 4 TB | 59 TB |
| CX700 | 256 | 240 | 4 TB(?) | 119 TB |
CX3 series
The CX3 series originally consisted of CX3-20, CX3-40, and CX3-80 models. Later the series was refreshed to include the CX3-10 and the 'i' and 'f' identifiers.| Model | Max. FC hosts | Max. disk drives | Initial capacity | Max. capacity (1 TB = 1012 B) |
|---|---|---|---|---|
| CX3-10 | 64 | 60 | 1 TB | 60 TB Terabyte The terabyte is a multiple of the unit byte for digital information. The prefix tera means 1012 in the International System of Units , and therefore 1 terabyte is , or 1 trillion bytes, or 1000 gigabytes. 1 terabyte in binary prefixes is 0.9095 tebibytes, or 931.32 gibibytes... |
| CX3-20 | 128 | 120 | 1 TB | 120 TB |
| CX3-40 | 128 | 240 | 1 TB | 240 TB |
| CX3-80 | 256 | 480 | 1 TB | 480 TB |
CX4 UltraFlex series
The CX4 UltraFlex 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 ExpressPCI Express
PCI Express , officially abbreviated as PCIe, is a computer expansion card standard designed to replace the older PCI, PCI-X, and AGP bus standards...
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 CX4 array consists of dual redundant hot-swappable components including storage processors, mirrored cache and battery backup, as well as redundant power supplies. The CX4 series supports Fibre Chanel and iSCSI host connectivity.
Major New Features in the CX4 UltraFlex Series include support for solid state flash drives, 64-bit FLARE Operating Environment and PCI-Express based SLIC I/O cards. The CX4-480 and CX-960 support fibre chanel solid state flash drives introduced by EMC for the Symmetrix DMX-4 in January 2008. Solid State Flash drives offer a significant performance advantage over mechanical drives and provide a new storage tier which EMC calls Tier-0. The new version of the FLARE operating environment that ships with the CX4 series includes support for the 64-bit Intel Xeon CPUs in the Storage Processors. The CX4 Series is also the first product to use the new PCI Express based SLIC I/O cards. The product-agnostic SLIC I/O cards provide more flexibility for future upgrades as new technologies become available, such as 8GBit Fibre Chanel and 10GBit Ethernet/iSCSI.
| Model | Cache Disk buffer In computer storage, disk buffer is the embedded memory in a hard drive acting as a buffer between the rest of the computer and the physical hard disk platter that is used for storage... | Front-end FC ports | Front-end iSCSI ports | Back-end ports | Max. HA Hosts | Max. disk drives | Max. capacity | Flash Drives |
|---|---|---|---|---|---|---|---|---|
| CX4-120 | 6 GB | 4 | 4 | 2 | 128 | 120 | 120 TB | Yes |
| CX4-240 | 8 GB | 4 | 4 | 4 | 256 | 240 | 231 TB | Yes |
| CX4-480 | 16 GB | 8 | 4 | 4 | 256 | 480 | 939 TB | Yes |
| CX4-960 | 32 GB | 8 | 4 | 8 | 512 | 960 | 1899 TB | Yes |
External links
- EMC CLARiiON Family EMC Corporation