Serial Attached SCSI - New
Interface, New Storage Rack?
In today's economy, delivering
high-density, scalable and
reliable storage
solutions to market quickly is a necessary for storage solution designer,
OEMs, system
integrators so they can keep the competitive edge they need for continued
success.
Serial Attached SCSI
has defined a device called an expander, allowing thousand combinations of
storage expansion to achieve the needs for IT professional on storage
availability, flexibility, scalability, and performance. However, with the
conventional method, this requires IT engineers to create many more complex
storage backplanes that may be dedicated to only one single solution.
The
limitation on conventional method backplane board
The predominant high availability physical interconnect technology
between the hot swap hard disk drives and storage host bus adapters reply on
transmission of data streams through a piece of physical PCB board (Backplane
Board). In Serial Attached SCSI systems the SAS expander is located on the
backplane as shown in fig 1 below. |
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With the conventional method,
all expanders are embedded on the backplane board. But because of the size of
the expander foorprint and/or other
IC components this can
increase the form factor IT engineers have to carefully balance the trade-offs
between reliability, scalability, performance and availability of the
application requirements. This flexibility limitation on the conventional
backplane design has forced designers to implement separate systems for each
type of solution and bear the costs of additional backplane design, addition
layers, prototypes, troubleshoot, manufacture and support. Failure of individual
components in a backplane means a complete replacement of a new backplane
causing single points of failure that can block access to the system, This
results in high support cost and increased total cost of ownership.
The
conventional method of backplane design (shown in fig 2 below) forces designers
to use more than 20 PCB layers, generates unnecessary signal skew, crosstalk and
DC interference, blocks airflow, restricts failed over and device addressability
as well as configuration flexibility and stands as a barrier to throughput
performance, storage scalability and system flexibility and availability. |
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| Are MLC SSDs Safe
in Enterprise Apps? |
This is a follow up
article to the popular
SSD Myths and
Legends which, a year earlier demolished the myth that flash memory
wear-out (a comfort blanket beloved by many
RAM SSD makers)
precluded the use of flash in heavy duty datacenters.
This new
article looks at the risks posed by MLC Nand Flash SSDs which have recently
hatched from their breeeding ground as chip modules in cellphones and morphed
into
hard disk form
factors. |
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It starts down a familiar
lane but an unexpected technology twist takes you to a startling new world
of possibilities.
...read the
article | | |
The new backplane and
daughter board
As the conventional backplane design method shown above has many
shortcomings for implementing SAS systems IT engineers require new solutions
that bring new levels of ease and simplicity.
The most important
characteristic of the new method developed by TST (shown in fig 3 below) is its
flexibility to support every storage solution available in the storage
world. This includes two physical parts: the Drive Backplane Board and
Expander Daughter Board. These two boards are connected with easy-swap
high-speed connectors and enables highly flexible storage topologies. The
backplane boards can support swappable daughter boards which are interchangeable
within the same enclosure and can be used to build high-availability systems
with no single points of failure. This method use the same backplane board for
multiple solutions, just by changing the Daughter board with the expansion
capability you require, will provide for a pay-as-you-grow platform so customers
can migrate to their unique solutions as needed. Because every solution uses the
same backplane, cost reduction then can achieved, In addition, it offers
competitive advantage in the marketplace by meeting compliance deadlines,
lowering the cost of building (as opposed conventional backplanes) and offering
reliable, user-friendly products to their end-customers ahead of any other
competitor in the marketplace.
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The new connection scheme
provides many benefits:-
- Backplane Manufacturer and Designer - Using the conventional
method, backplane designers and manufacturers need to develop many backplanes
for each solution, the emergence of SAS and the new backplane design enables
manufacturers to develop only one backplane. Vendors can use the same Stock
Keeping Unit (SKU) to support many types of storage application, resulting in a
much less expensive board.
- OEMs - The Emergence of SAS and this backplane solution means that
OEMs can now sell standard backplanes and easily upgrade daughter boards. The
use of this flexible solution shortens design time, simplifies inventory
management, result in faster design, less validation efforts, reduces costs
while maintaining margins and profitability
- VARs and System Integrators - Serial Attached SCSI and the new
backplane technology enables VARs and SIs to save time on integrating custom
solutions, simply by changing the preferred daughter board. VARs no longer need
to worry about stocking or integrating a wrong solution. Instead, they can
simply populate the backplanes with the desired daughter board. Overall benefits
include reduced inventory costs, easier product differentiation, simplified
training, support, and reduced cost of ownership.
- End users - benefit from the cost reductions from backplane
manufacturers, OEMs and VARs, plus the ability to change storage solutions
without purchasing new chassis systems simplifies the upgrade process and helps
future-proof end-user investments.
Serial Attached SCSI will offer a
new level of performance and data availability. The new backplane empowers
customers with great flexibility. IT designers and users will be able to quickly
and easily design storage systems where all these elements can be used without
additional system and support costs.
...TST profile |
| Can You Trust Your Flash
SSD's Specs? |
Editor:- I've noticed is that
the published specs of
flash SSDs change
a lot -from the time a product they are first announced, then when they're
being sampled, and later again when they are in volume production.
Sometimes
the headline numbers get better, sometimes they get worse. There are many good
reasons for this.
The product which you carefully qualified may
not be identical to the one that's going into your production line for a
variety of reasons... ...read the article | |
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