On a Clear Path
Plan on significant storage capabilities to handle bandwidth
- By Tom Larson
- Nov 01, 2014
For those looking for a defined migration strategy to network video,
the path can appear muddled. Today, there are countless manufacturers
that claim to have a clear migration path toward an open architecture
platform; however, there is simply no clear path that applies
to all applications.
Even though organizations, such as ONVIF, are working toward industry
standards, the lack of interoperability in many video system products is a serious
concern for planners and integrators. This is especially true when it comes
to mission-critical functions. Supporting high-resolution cameras from multiple
manufactures requires significant storage and server capabilities to handle the increased
Purpose-built, Video-optimized Servers
When designing or migrating toward a new IP-based physical security solution, it
is imperative to use a server and storage solution that is purpose-built and optimized
for video applications. A best-practice video server demands mission-critical
quality drives with high I/O capabilities and unconstrained workload capacity.
Server configuration is vital and should include memory, storage and processor
specifications that ensure optimum scalability for video. Video servers should have
the capacity to accommodate future growth, including the ability to record higher
resolutions and higher frame rates without dropping frames as well as cost-effectively
store video data for longer periods of time.
In 2010, before the heavy influence of high-megapixel cameras, the introduction
of 6G SAS drive technology into the video market offered significant system
advantages over historical SATA drives. These bi-directional drives provide two
redundant paths to every hard drive for increased availability and reliability in case
of a single-path failure.
The high I/O workload of network cameras can constantly inundate servers,
as client workstations on the other end simultaneously attempt to pull video for
review. Both slower speed and SATA drives can cause significant bandwidth issues
directly due to the buffering that is required with single channel data transfer.
This lag can result in dropped or frozen frames, video artifacting and a number
of other issues.
Mission-critical IP video applications require greater protection than typical,
off-the-shelf IT data servers, regardless of size and scope. Therefore, the importance
of using 6G SAS drive technology in IP-based physical security solutions
cannot be understated.
Types of Storage Technology
Storage of video in a typical network video solution can be an immense proposition.
It could entail potentially hundreds of high-resolution cameras capturing as
many as thirty frames-per-second, operating 24x7 for a month or up to a few years.
The most common mistake made is to categorize streaming video as just another
form of data. The case for purpose-built video storage over traditional data solutions
focuses on five key areas: massive database size needs, I/O-intensive operations,
intolerances of system latencies, constant bit-rate streaming and demanding
operating environments, such as temperature, vibration and bit-error rate. Because
of the intrinsic nature of streaming video, each of these five areas requires a purpose-built approach that takes into
account unique needs, capabilities and
system demands. Three main storage
technologies that are typically used in
the IP video market include:
Internal storage. This technology
records the video to the internal drives
within the server. The logistics of having
the drives inside the main CPU
dictates no faster throughput for video
data. These drives should be protected
by RAID 5 or 6, ensuring that if a drive
was to fail, no data would be lost. Today’s
scalable servers can house up to
240TB, all internal to the server, in as
little as 5U of rack space.
Using internal storage is the most
popular, as it offers the best performance
at the best price point. Video
recorders should run in a single-application
being, recording the video. Today’s
enterprise-grade IP video servers eliminate
the expense and potential risk of
running archive video over a virtualized
solution in a shared environment.
Directed attached storage (DAS).
This high-end technology is used
when there is not enough drive space
available within the server chassis.
Because of its multi-lane SAS connection
to the server, DAS performs
almost identically to the internal storage.
These drives should be protected
by RAID 5 or 6, ensuring that if a
drive was to fail that no data would be
lost. DAS can be scaled up to 1680TB
from a single server using as little as
22 rack spaces.
More importantly, properly-optimized
DAS solutions can manage more
than 1,000MBit/s of video ingestion.
With the properly-built DAS, latency
is reduced as data does not travel over
large distances. Today’s DAS technology
allows a security integrator to map
cameras to one single drive partition
instead of having to split the loads via a
number of partitions.
Centralized storage (iSCSI). This
technology is used when the end user
would like to store video in a central location.
iSCSI allows for multiple servers
to send their video data across the
network to a centralized storage array.
This storage technology, although
popular in the IT world, is not as effective
in the video world. This is due
to other considerations that need to
be addressed in order for the solution
to properly work. The iSCSI storage
device is only as fast as the network
to which it is attached, regardless of
SATA or 6G SAS drives installed. Once
through the network, the 6G SAS drives
will outperform the SATA drives, similar
to within the internal server.
The storage array design must take
into consideration the potentially large
amount of data that could be streaming
from multiple video servers. It is
crucial that the storage array ingests
the total bandwidth from all the servers
simultaneously without bottlenecking.
The iSCSI storage solution can no
longer be considered as a Just a Box of
Disks (JBOD) device. More than ever,
today’s video applications depend on
these units having enterprise-server
standards such as health monitoring,
storage controller clustering, mirrored
OS disks, redundant fans and power, and advanced memory protection.
Read the Fine Print:
What is the Warranty?
Warranty seems to be a lot like an
opinion, everyone seems to have one.
Unfortunately, warranty needs to be
based more on fact than opinion. It is
important for the integrator to check
those facts during the purchase decision.
If the video recorder is down,
the cameras aren’t recording. Suffice
to say, the constant recording of the
video is the key element of the project.
Consider that the security integrator is
generally on the hook for the three-tofive
years of a security project, and yet,
the warranty tends to get overlooked,
until it is too late.
Determine the facts up front:
- Is the entire video recorder under one
on-site agreement or are some or all
internal parts—even critical parts
such as the hard drives – not covered?
If so, who is servicing those?
- Are they on a mail-in warranty or
perhaps they are advance exchange?
- Are the replacement drives sent overnight,
or do you pay the additional
freight to get them the next day?
- When the drive does arrive, are you
then the on-site tech or does the
server company dispatch someone
at their expense?
- What value do you put on your
manpower if your company needs
to go on-site and follow-up on a
- Can you afford two service calls if
you need to pull a drive today and
then come back tomorrow or the
next day to install the new one?
- What is the integrator and end-customer
cost for processing an RMA
versus a product that needs no
- What is the potential financial impact
of the down customer as it relates
to future opportunities or your
company’s reputation? Did your upfront
system savings become a distant
memory? Have you subjected
your customer to liabilities due to
missing critical footage?
Seems the integrator has enough
on their plate without having to walk
through the warranty maze. As much
as server manufacturers strive for the
utopia of 100 percent up time, things
happen that require immediacy and
stability—without guesswork or added
costs to their bottom line. Today’s
enterprise-grade video recorders offer
active health features which continually
monitor the system status. Proactive
alerts of potential failures will be
sent before they occur. This allows the
project server virtually zero down time
throughout the length of the project
Regardless of the brand, the integrator
should ensure the entire video
recorder is covered by a full-system,
on-site warranty, both inside and out.
Otherwise, an integrator is buying five
years of expense and
This article originally appeared in the November 2014 issue of Security Today.