Analysis

posted on 31 March 2008 15:07

Multi-tiered SAN array vendor Xiotech is going to announce a highly scalable and reliable array built with components containing 20 hard drives and dual controllers These are Integrated Storage Elements (ISE) and they are virtualised into a single and self-healing storage pool.

The ISEs presents a block-structured storage resource to servers across a storage area network (SAN). The ISE scheme details are revealed in patent applications made by Stephen Sicola, now chief technology office (CTO) for Xiotech but previously general manager for Seagate's Advanced Storage Architecture group, which Xiotech bought earlier this year in a $40 million transaction.

Xiotech is, in effect, productising Seagate-owned and invented technology. Xiotech and Seagate have a deeply intertwined relationship, which also features Atrato, the startup which only this month has launched the accelerated I/O, self-healing and scalable Velocity1000 storage product.

Sicola Patents

• A US patent application, 2006/0277380 A1, made on December 7th, 2006, refers to a distributed storage system with global sparing.
• It is a continuation on part of an earlier patent aplication, number 11/145,403,  filed on June 3rd, 2005.
• A third application, number 20070011425, refers to restriping data in a distributed storage system.
• A fourth, number 10/884,605, is entitled Carrier Device and Method for a Multiple Disc Array.
• A fifth, number 10/817,264, is entitled Storage Media Data Structure and Method
• Number 10/817,617 is entitled Managed Reliability Storage System and Method
• Number 11/040,410 is entitled Deterministic Preventive Recovery From a Predicted Failure in a Distributed Storage System
• Number 11/145,404 entitled Storage Array with Enhanced RVI which efers to near zero rotational vibration and high cooling efficiency.

There are very probably more.

Timeline

• 1995 - Xiotech founded in Minnesota.
• 1999 - Seagate bought Xiotech for $360 million. Atrato founders Dan McCormick and Jonathan Hall are both on Xiotech staff.
• 2002 - Seagate sold 80 percent of Xiotech to Oak Investment Partners and firm become independent under CEO Casey Powell.
• 2003 - McCormick leaves Xiotech. Seagate starts up its Advanced Storage Architecture (ASA) group. Steve Sicola becomes its general manager. Dr Ellen Lary becomes a consultant. Sicola was CTO for StorageWorks at Compaq. Lary was VP Business Critical Storage at Compaq. Both were at DEC when it was bought by Compaq. ASA is located in Colorado Springs.
• 2003 - McCormick and Hall start up Sherwood Information Services in Minnesota.
• 2004 Sherwood Information Services becomes Atrato which was incorporated in 2004, and located in western Colorado.
• November, 2007 - Xiotech raises $40 million to buy ASA which Seagate no longer wants. The funding round was led by the chairman of Seagate's board, Steve Luczo, who becomes a director of Xiotech. Sicola becomes Xiotech's CTO and Lary runs ASA inside Xiotech as its Advanced Solutions Group. Xiotech gets new CFO skilled in running finance operation for merged companies. The previous CFO, Steve Snyder (Steve number 3 in this story) becomes head of Xiotech's Stoage Solutions Group.
• March, 2008 - Atrato launches Velocity1000
• April, 2008 - Xiotech to launch ISE product.

Xiotech

The company's president and CEO is Casey Powell. Xiotech's main products are its Magnitude 3D 4000 and 3000 multi-tiered SAN arrays. These present a thinly-provisioned, clustered and virtualised block storage pool across two tiers of fibre channel disks and a third tier of serial ATA (SATA) drives. The product can be accessed across both Fibre Channel (FC) and iSCSI SAN links. Xiotech sells the product both direct and through its channel to mid-range customers.

In July, 2006 it added a solid state disk (SSD) tier or cache to the Magnitude 3000 product line as an I/O speed booster. The newer 4000 cannot have an SSD tier. When EMC added SSDs to its Symmetrix arrays earlier this year Xiotech's pioneering use was forgotten.
 
It is perceived to have been eclipsed in market regard in the last five years or so by Compellent, EMC, EqualLogic and NetApp. There are also stories of a poorly-received channel program. A new VP for channel development, Mike Gluck, was appointed earlier this month.

A perception is that Xiotech and its investors want to use ISE to drive Xiotech's revenues higher so that an IPO can take place enabling the investors to profitably exit the company.

Background

The patent applications present a background in which storage intelligence has moved from servers into network devices which means groups of servers can let one box take care of things such as storage allocation, backup and fault-tolerance. But this doesn't solve the problem of adding more capacity or moving data from one storage device to another as the host servers and the networks need to be made aware of this.

One patent application states: "What is needed is an intelligent data storage subsystem that self-deterministically allocates, manages, and protects its respective data storage capacity and presents that capacity as a virtual storage space to the network to accommodate global storage requirements. This virtual storage space is able to be provisioned into multiple storage volumes. A distributed computing environment uses these intelligent storage devices for global provisioning as well as for global striping and restriping of stored data. "

ISE Technology

An ISE is composed of two multiple disk assemblies (MDAs) Each MDA has dual redundant controllers looking after two sets of ten RAID-protected SATA or FC disk drives. (The patent application specifies that SSDs cpuld be used instead.) Two of these are in-place spares to guard against drive failures. The two MDAs are connected via a mid-plane to dual redundant power supplies, battery backup and interface modules.

Different MDAs can be produced to optimise for performance (FC drives) or capacity (SATA drives.)

The controllers have intelligent storage processors and operate with them to provide managed reliability of data integrity on the drives. The ISPs look after routing, volume management, and data migration and replication. The controllers create LUNs (logical unit numbers) or virtual storage volumes. Such a volume can run acoss one or more ISEs. Data can be striped across LUNs. As LUNs are expanded the restriping can be accelerated through the placement of controllers and ISPS close to blocks of drives.

ISEs, which are fault-tolerant, are connected across a switching fabric and do not have to reside in the same datacentre. An ISE constitues a rack shelf, thought to be 4-5U high.

If 1TB 3-5-inch drives are used an ISE can hold 32TB of raw capacity plus 8TB of spare capacity. Each MDA can withstand two drive failures before it needs to have failed drives removed and replaced. An ISE self-heals from drive failure by reconstituting the data on a spare drive.

Accessing servers can access the ISEs using FC, iSCSI or SAS protocols.

Atrato Comparison

Atrato's Velocity1000 is also a virtualised, highly scalable and self-healing array but it has accelerated I/O which the ISE does not. It also uses sealed units with the smallest one holding around 32 2-5-inch drives. Four of these make up a sub-unit and there are two sub-units per Velocity1000 providing up to 50TB of raw capacity in a 3U rack enclosure.

Xiotech's expected announcement

It is expected that Xiotech will announce a distributed and clusterable Magnitude ISE product with very high scalability and a self-healing capability using fail-in-place drives enclosed in sealed pairs of MDAs. The product will be marketed with attributes of scalability, high reliablity and consequently lower management and ownership costs.

^{[Chris Mellor.]}