ATTO Technology Diamond Storage Array VT-Class - Manual (Page 15)

4
Technical overview
ADXT Powers ATA to New Levels
The original notion of RAID was to build high
capacity, reliable storage subsystems using large
numbers of inexpensive disk drives. Thus its
original definition: Redundant Array of
Inexpensive Drives. Over time that definition
became Redundant Array of Independent Drives
and the inherent cost advantage in a RAID system
was lost. The Diamond Series provides a high
capacity, high performance and highly reliable
disk array that uses the merged power of many
inexpensive ATA disk drives.
Intelligent Midplane The heart of the Diamond
Series storage array is the intelligent midplane
with ADXT
to sum or aggregate the data rates of
individual ATA disk drives to create high data
transfer rates. This technology enables features
such as serverless backup, advanced error
protection, metadata storage techniques,
virtualization software, thermal management and
advanced enclosure services.
The midplane contains a combination of custom
Application Specific Integrated Circuits (ASICs),
processors and proprietary embedded software. It
is divided into three main processing sections
which handle the data being read or written to the
ATA disk drives from the Fibre Channel or SCSI
host interfaces. The Virtual Device Manager
(VDM), Data Routing Fabric (DRF) and ATA
Interface Engines (AIE) organize data streams for
storage or retrieval.
Virtual Drive Manager Data is accessed through
Virtual Drives using an implementation of the
standard SCSI protocol controlled by the Virtual
Device Manager. The VDM adds capabilities
such as RAID, data management services,
enclosure management services, serverless
backup, data replication using SCSI Extended
Copy and LUN mapping.
Data Routing Fabric Incoming or outgoing data is
routed between the ATA Interface Engines (AIE)
and the Fibre Channel or SCSI interface by the
custom Data Routing Fabric ASIC, a high speed,
low latency transfer fabric with more than 2
GB/sec. of bandwidth supported by up to 512
Megabytes of memory.
ATA Interface Engine (AIE) The interface to each
pair of drives is through a custom ATA Interface
Engine ASIC. The AIE implements the typically
software-intensive ATA interface completely in
silicon. Each AIE contains a dedicated ATA
protocol processor to completely automate
command and protocol processing. Automated
command overlapping and queuing maximizes
the performance of multi-threaded I/O. The AIE
transfers data using double-clocking technology
at 66 megabytes per second. The Diamond-VT
contains 12 AIEs for a parallel transfer rate of 792
megabytes per second. In
addition to guaranteeing
data transfer integrity with
automatic CRC checking,
the command and status
transfers are validated
using a patent pending
technology unique to the
AIE.
text
Disk 1
Disk 2
AIE
1
Disk 1
Disk 2
Disk 1
Disk 2
Disk 1
Disk 2
Disk 1
Disk 2
Disk 1
Disk 2
Disk 1
Disk 2
Disk 1
Disk 2
Disk 1
Disk 2
Disk 1
Disk 2
Disk 1
Disk 2
Disk 1
Disk 2
DATA ROUTING FABRIC
VIRTUAL DEVICE MANAGER
FIBRECHANNEL
INTERFACE 1
FIBRECHANNEL
INTERFACE 2
AIE
2
AIE
3
AIE
4
AIE
5
AIE
6
AIE
7
AIE
8
AIE
9
AIE
10
AIE
11
AIE
12