RAID Introduction

System Application Block Diagram

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RAID 1

ATA2ATAR01 Setting:

ATA Connectivity: Maximum 2 ATA drives.
Installation: To provide hot-swap and hot-rebuild features
KTCIDEMR will be needed.

LCD Message information:

RAID 1 (Disk mirroring), it would access data with both HDDs
at the same time. So it can provide higher data access reliability.
When some error happened in one HDD of the RAID system,
the other HDD could keep the system working.

Advantage:

• Support higher data access reliability and enhance data storage
  safety and stability.
• Support HDD Hot-Swap function.
• Support auto-rebuilding function.
• Support detection and recovery routine of disk bad sector.

Disadvantage:

• 50% capacity is the cost for composing a RAID 1 system.

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RAID 0

ATA2ATAR01 Setting:

ATA Connectivity: Maximum 4 ATA drives.
Installation: No hot-swap and hot-rebuild features.

LCD Message information:

RAID 0 is the fastest RAID mode about the HDD data access
rate. It focuses on performance enhancing primarily. Data would
be distributed to two or more HDDs and the total storage capacity
would be the sum of all HDDs. Due to data distribution and
concurrent data access at various HDDs, It could enhance
performance and sum storage capacity.

Advantage:
RAID 0 provides better performance than single HDD. In theory,
because data distributes averagely to each HDD of RAID, the
promotion of the data access rate could reach to 200%. Usually
this RAID level applies to the system that needs high performance.

Disadvantage:
RAID 0 doesn't support data backup and any failure tolerance.
Because data distribute to multiple HDDs,when there is something
wrong with one HDD, the system would be influenced. Since
RAID 0 has a reliability misgiving problem, it isn't suitable for
data storage that needs to save for long time.

 

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NRAID (SPAN)

ATA2ATAR01 Setting:

ATA Connectivity: Maximum 4 ATA drives.
Installation: No hot-swap and hot-rebuild features. for maximum
4 ATA drives.

LCD Message information:

N-RAID (Non-RAID) is another application of RAID. Main function
of it is "Spanning" that means multiple HDDs will be compose
to one for big capacity and capacity could be expanded all the
time by one new HDD adding.

Advantage:

• Just use one IDE/SATA Channel to expand capacity.
• In theory, the maximum extensible capacity of N-RAID is 128P
  Byte approximately to 134217728GByte (48bit addressing).
  The maximum HDD number of a KTC NRAID system is 16.
• Extending capacity on the go and no data loss.

Disadvantage:

• No failure tolerance
• No data access rate improvement
• The failure of one HDD will result in the failure of the system.

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JBOD (X_M/Y_S Hot Swap)

Set the JBOD mode, if you have only one HDD.

ATA2ATAR01 Setting:

ATA Connectivity: Maximum 2 ATA drives.
Installation: To provide hot-swap features KTCIDEMR will be needed.

LCD Message information:

Just a Bunch of Drives (JBOD), this mode just support one master
device (X-Port) and one slave device (Y-Port) with each ATA channel.

Advantage:

• High system compatibility.
• In external storage system, it could be used as mobile rack
  box.

Disadvantage:

• Each ATA channel supports only one device, so JBOD could
  connect two HDDs only.

MORE INFORMATION AVAILABLE AT ATA2ATAR01