RAID Storage Systems

RAID Storage Systems

We provide RAID storage systems for a wide variety of operating systems and applications.  The RAID storage systems we supply are fully approved to work with the following Virtualization technologies VMware, Hyper-V, Citrix as well as storage for Video, CCTV, Post Production, D2D, backup/archiving, The Cloud, Datacenters and many other applications.  Many of the RAID storage systems also have the ability to save energy by powering down individual spindles or volumes, they come with 3 years warranty and 5 years optional.RAID Storage System

If you need 7×24 support and a range of Enterprise features and functionality then we recommend and provide the Fujitsu ETERNUS DX that holds many world record benchmarks and is surprisingly easy to manage.  Alternatively, we can provide a Proware 64 bay FC chassis with active-active controllers.

RAID Storage Features

When looking at purchasing disk system some important things to consider are as follows:

  • What type of hard disk drives to you want to use 2.5″ / 3.5″,  SAS or SATA, disk capacity, rotational speed?
  • What redundant features does the disk storage have?
  • Can the storage be expanded?
  • Can you mix drives i.e. SAS / SATA / SSD?
  • What host interface do you need i.e. Fibre Channel, SAS, iSCSI, NAS, Unified?
  • How many interface ports does the storage have?
  • What application will the disk storage system be used for?
  • Is the storage vendor application approved?
  • What support and warranty options are available?

SSD drives

Many RAID storage systems today have the ability to accept SSD drives.  There are two models of SSD drives available Consumer or Enterprise.  The difference is the price as Enterprise drives are considerably more, but they provide features and functionality which consumer drives lack.

  • Many Enterprise SSD drive vendors incorporate power safe features, which saves the last writes in flash using capacitance, should the power fail.  When power is restored the data in the flash is written first.
  • Enterprise SSD drives are tested under worst case workloads, in order to ensure sustained and consistent performance
  • Enterprise SSD drives to deliver better and more stable IOPS when under load
  • Enterprise SSD drives also have better write algorithms and more cache to cope with bad blocks
  • Enterprise SSD also has a better warranty and support which is part of the initial cost

If you need high performing and reliable SSD drives, stick to Enterprise class models as you will have fewer issues and better performance.

Disk Drives

It is a well-known fact that Enterprise disk drives are twice the price of the equivalent desktop model, why is this?  For starts lets look at the following:

  • Desktop drives normally have a 1 – 3-year warranty vs 5 years for enterprise drives
  • Desktop drives are not designed for 7×24 operation
  • Desktop drives cannot handle thermal re-calibration of the drive heads
  • Desktop drives typically have less on-board cache
  • Desktop drives use lower grade components
  • Desktop drives tend to have more bad block errors than the enterprise drive equivalent

If a desktop drive is used in a RAID storage system whilst it may be certified by the storage vendor, the disk drive manufacturers take a different approach.  Should something happen with you desktop drives whilst they are used in a RAID the disk storage vendors will not offer assistance as you have used the wrong drives in the RAID storage system.

With 8TB drive capacities available the rebuild times or complete data loss of a RAID system using 16 desktop disk drives is a huge amount of data to risk to save money on the upfront purchase.

SAS vs SATA?

When purchasing a RAID storage system the type of drives that we install can affect the price, performance & reliability of the disk storage. A SAS (Serial Attached SCSI) at higher spin speeds has a lower storage capacity these being 15k 600GB for a 3.5″ drive.  SATA (Serial Advanced Technology Attachment) is slower only spinning at 7.2k, the exception to this is the WD Velociraptor which spins at 10k.  A SATA disk will plug into a SAS disk slot but it will not work the other way round.

Speed table

The SAS and SATA speeds are shown below.

SATA-I – 1.5Gb/s SATA-II – 3.0Gb/s SATA-III – 6.0Gb/s
SAS-I – 3.0Gb/s SAS-II – 6.0Gb/s SAS-III 12.0Gb/s

Reliability and Performance

A SAS disk drive is more reliable than SATA as it can handle errors better, due to SAS having a bigger Common Command Set (an instruction set) that allows the drive to handle errors in a more efficient way than SATA.  Due to the increased instruction set, an SAS drive has and its ability to multitask an SAS drive of the same disk capacity and spin speed of it’s SATA disk sibling will perform 10-20% better.

Disk Drive Table

When choosing which disk storage system to purchase another consideration is the size, speed and capacity of the disk or SSD drives we can supply.  The largest available disk drive at the moment is 8TB SAS 12Gb/s or SATA 6Gb/s interfaces available in enterprise versions, 12TB drives will be available in 2017!  The largest SSD drive currently available is 2TB with SAS 12Gb/s or SATA 6Gb/s interfaces.  The highest capacity 2.5″ disk drive is 1.8TB with SAS 12Gb/s or SATA 6Gb/s.  The disk manufacturers we supply are WD/HGST/Seagate/SanDisk/Samsung/Kingston.  Call us for pricing and availability.

RAID Storage Summary

The RAID storage systems we supply provide a huge range of host interfaces, disk drive support, application and operating system connectivity as well as providing:

  • Great value for money
  • Redundant features
  • Reputable brands
  • Performance / Reliability
  • After sales support

At one stage the price delta between an SATA disk drive vs an SAS amounted to a considerable difference, today that is not the case as an SAS disk it is typically 10-15% more, therefore if you can afford to we would always choose SAS over SATA.  Call us on 01256 782030 with your storage requirements and see how we can help.

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