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RAID controller news
Anticipating demise of RAID controller market...

LSI will Compete with Fusion-io


Editor:- January 26, 2010 - LSI and Seagate today announced they have collaborated on designing PCIe SSDs for the enterprise accelerator market which will sample in Q2 2010.

Editor's comments:- LSI approximately the 163rd company to enter the SSD market (not counting SSD SoC makers - which would push the score to about 185).

Partly LSI's move is due to a strong suction effect from the SSD market bubble - and partly an inevitable step given that the high end of the RAID controller market is going to disappear.

There's little point in spending money aggregating IOPS in an array of hard disks - if the result costs more, is slower and is less reliable to operate.

In Q4 2009 - PCIe was the #1 most popular form factor for SSD related searches. (Higher than than for 2.5" SSDs.) In the same quarter the single most popular company profile viewed by readers was PCIe SSD evangelist Fusion-io. Dozens of oems have already entered this market - thereby preparing the educational framework for user acceptance of this technology.


New Directory for AoE Storage

Editor:- January 15, 2010 - StorageSearch.com today published a new directory for AoE (ATA-over-Ethernet NAS Storage).

Although this NAS mode first hit our news pages in 2003 - support for it has been miniscule and compatible products are only available from a handful of vendors. Will 2010 be the year that it all changes? Maybe. SSDs could play a part - because less latency is wasted in this low level network storage interface.


LSI Samples 600k IOPS ROC for SSD Servers

Editor:- December 16, 2009 - LSI announced it is sampling the LSISAS2208 - a dual-core 6Gb/sSAS RAID-on-Chip IC to OEM customers.

It's intended to support the forthcoming PCIe 3.0 specification, currently under development and provide performance levels that meet the needs of next-generation server platforms based on flash SSD storage (up to 600,000 IOPS).


Error Correction in MLC Flash SSD RAID

Editor:- October 28, 2009 - ECC Technologies has published a new article which examines data reliability issues in RAID systems using MLC flash.

In his survey of RAID and error correction related to SSDs the author Phil White said he thinks that "MLC NAND Flash memories should implement nonbinary error-correcting codes such as a Reed-Solomon (RS) codes so that all of the bits from one cell are in one symbol. The communications industry has been doing that for decades, but the Flash industry has been implementing a scheme that forces the bits from one cell to be in separate records (pages) so that one cell failure can cause multiple binary symbol failures – which seems illogical."

I asked him to expand on this for our readers.

In reply - Phil said he doesn't think that most NAND Flash (SSD) companies have a high level of expertise in the field of error-correcting codes.

"Many of the NAND Flash controllers that are out in the market now have ECC Tek's ECC designs in them. None of the controller companies who have come to us have any idea how to implement binary BCH encoders and decoders in hardware. I doubt if any of the Flash manufacturers have that expertise either."

"For years the Flash manufacturers implemented a simple binary scheme that corrected only 1 bit in a page. I don't have evidence to prove this, but I believe the NAND Flash manufacturers simply decided to extend their original scheme to correct N bits in instead of 1 bit to handle higher error rate devices. I also believe that they implemented a scheme for MLC NAND Flash to "randomize" the errors when a cell fails.

"Consider 4-bits/cell. When a cell fails, 0-4 bits may be in error. In order to keep using binary error-correcting codes that only correct bits, they designed the chips so that all of the bits from that cell are in different pages.

"To the best of my knowledge, they never considered using RS codes so that all of the bits from one cell are in one RS symbol. For example, assume a RS code with 12-bit symbols. Each RS symbol can hold the data from three 4-bit cells, and if those three cells happen to fail, it will only corrupt one RS symbol. RS codes can correct t "symbol" errors and s "symbol" erasures as long as 2t+s is less than or equal to R where R is the number of "symbols" of redundancy. The most natural and powerful thing to do is to put all of the bits from one cell in one RS symbol." ...read the article

See also:-
Data Integrity Challenges in flash SSD Design - a recently published article by SandForce.


OEMs Qualifying Virtual RAID Adapter Software

Editor:- September 15, 2009 - Dot Hill today announced that several tier #1 OEMs are evaluating its virtual RAID adapter software.

VRA-based solutions enable server OEMs to offer built-in, high-end RAID functionality in multi-core Intel compatible servers without the expense of a dedicated RAID-on-chip acceleration device.

In September 2008, Dot Hill acquired certain assets from Ciprico which included exclusive rights to license RAIDCore technology from Broadcom. The acquisition was part of a strategic initiative to offer software-only products for the enterprise server data protection market as complementary offering to its existing external hardware RAID array business.

RAIDCore VRA technology enables RAID to be offered in volume, entry-level servers where hardware-accelerated RAID has traditionally been too expensive.


Adaptec Ships Flash Cache Backup for RAID Controllers

Editor:- June 24, 2009 - Adaptec today announced the availability of flash backup options for its SATA/SAS RAID controllers.

Adaptec's Zero-Maintenance Cache Protection protects data stored in controller cache for up to 10 years with no installation, monitoring, maintenance, disposal or replacement costs unlike lithium batteries.

Editor's comments:- the industry's 1st flash cache backup module for RAID controllers was announced in February 2009 by Viking Modular Solutions.


RAISE Joins RAID lexicon

Editor:- April 15, 2009 - this week SandForce has added a new word to the rich RAID lexicon with their new word - RAISE (which stands for - Redundant Array of Independent Silicon Elements).

RAISE is the label for the RAID-like protection scheme which their SSD controller uses inside 1.8" and 2.5" flash SSDs.

Although the word is new, the concept is not.

Manufacturers such as Texas Memory Systems, Violin Memory and Fusion-io have used similar schemes inside their rackmount SSDs and PCIe SSDs for some time.


LSI Announces SSD Aware RAID Features

Editor:- March 10, 2009 - LSI has announced better support for flash SSDs in the latest update to its MegaRAID SAS adapters.

LSI calls this feature SSD Guard - which can anticipate some types of flash SSD failures in RAID 0 configurations and starts rebuilding data on a spare unit.


Viking Launches SSD Backup Module for RAID Cache

Foothill Ranch. Calif. - February 18, 2009 - Viking Modular Solutions announced ArxCis-NV - a flash SSD based backup for cache memory in RAID controllers.

"Current technology of backing DRAM modules with batteries provides protection for approximately 72 hours and also brings a host of battery related issues to IT managers. ArxCis-NV products help eliminate these issues..." said Adrian Proctor, VP of Marketing for Viking Modular Solutions.

The ArxCis-NV is a JEDEC edge compatible registered DRAM module with ECC which can write to its associated embedded SSD at 80MB/s triggered by a drop in rail power. The module hold-up power (typically 10 to 15 seconds, depending upon DRAM density) is supplied by Supercapacitors, which only require 10 seconds to fully charge. ...Viking profile
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storage history - RAID controllers - 2001, 2002, 2003, 2004, 2005, 2006
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RAID controller oems
ACARD Technology

Accordance

Accusys

Adaptec

Addonics Technologies

AMCC

ATTO Technology

Broadcom

CEI

Ciprico

Cyclone Microsystems

Data Protection Solutions

Digi-Data

HighPoint Technologies

HP

Infortrend

Intel

JMicron

LaCie

LSI

Marvell

NetCell

Norco Technologies

Pivot3

PLX Technology

Promise Technology

QSAN Technology

Silicon Image

Super Micro

Ultera Systems

Xyratex
still can't find it? check the acquired, dead & renamed list
IC's
ICs

Flash Memory
Flash Memory

serial SCSI
Serial Attached SCSI
There are hundreds of articles about SSDs on StorageSearch.com
Here, below, are some examples.
  • RAM Cache Ratios in flash SSDs - it's important to know the underlying RAM cache architecture - even if you're happy with the R/W and IOPS performance.
  • 2010 - 1st Fizz in the SSD Bubble? - even the dogs in the street know this is going to be a multibillion dollar market. Greed will play as big a part as technology in shaping the SSD year ahead.
  • the pros and cons of using SSD ASAPs - auto tuning SSD appliances are a new category of SSD which entered the market in the 2nd half of 2009 to accelerate servers without needing human tune-ups. How can you tell if they are right for you? And how well do they work?
  • the Problem with Write IOPS - in flash SSDs - long established as a useful performance modeling metric - this article explains why some specs are exaggerated when applied to flash SSDs - or predict the wrong results for many common applications.
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click to read article by Texas Memory Systems
Using SSDs to Boost Legacy RAID and Database Performance - article by Texas Memory Systems

Adding a solid state disk to inter-operate with an existing RAID storage system can be like sprinkling fairy dust which makes everything go faster. That's often cheaper and more effective than upgrading servers and licenses or replacing existing storage. ...read the article, Solid state disks
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click to read RAID article by Infortrend
10 Ten Tips for a Successful RAID Implementation

article by Infortrend

In the 20 years since I first worked on RAID I've read and published countless articles about this subject.

So what can a new RAID article tell you?

Plenty of practical stuff - from a modern perspective. ...read the article , ...Infortrend profile
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read the serial scsi article by Adaptec
the Benefits of SAS (Serial Attached SCSI) for External Subsystems - article by Adaptec

This introduction to Serial Attached SCSI gives you an idea of the performance, compatibilities, applications and roadmap for this new directly attached disk connection standard. With throughput capability faster than 2Gbps Fibre-channel systems and faster than ultra320 SCSI - the new SAS products not only provide an upward migration path for parallel SCSI applications but also open the door to a new class of high performance high reliability enterprise systems. ...read the article, ...Adaptec profile, Serial Attached SCSI
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click to read RAIDn article by Tandberg Data
The RAIDn Algorithm - How Does it Compare? - article by Tandberg Data

If you think you know RAID because you use RAID level 5 and all that ancient technology from the 1980s then think again.

The newer RAID algorithms today provide better data survival when you get multiple disk failures and provide a higher percentage of usable storage. ...read the article, ...Tandberg Data profile, RAID systems, RAID controller cards

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