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EXECUTIVE SUMMARY
Deploying Affordable, High
Performance Hybrid Flash
Storage for Clustered SQL Server
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Flash storage adoption has increased in recent years, as organizations have
deployed it to support business applications.
PCIe flash memory is dramatically faster than solid-state drives and unique
QoS technology from NexGen Storage™ guarantees predictable application
performance.
IT teams can maximize SQL Server performance through storage best
practices, including the use of flash storage.
ESG found that NexGen’s end-to-end flash storage solution significantly
improved performance in SQL Server clustered environments.
By delivering enhanced database application performance, NexGen’s PCIe
flash solutions reduce IT costs and improve business operations.
Michael Otey, Senior Technical Director, Windows IT Pro, SQL Server Pro
Mike Leone, Lead Lab Analyst, ESG
Vincent LaPaglia, Senior Storage Engineer, NexGen
Sponsored by:
EXECUTIVE
S U M M A RY
Deploying Affordable, High Performance Hybrid
Flash Storage for Clustered SQL Server
Overview
In recent years, flash storage implementation
options have increased and many organizations now use this technology on servers to
improve application performance. In SQL
Server environments, flash storage eliminates
many traditional storage controller and protocol bottlenecks. It is well suited for data files,
log files, indexes, and tempdb.
Lab validation by ESG found that the
NexGen™ and NexGen SPX products increased average response times and supported many more transactions per second
than traditional SANs.
Context
The panelists described how flash storage
solutions like those offered by NexGen can
improve performance for clustered SQL
server environments.
close to half of organizations (49%) use
solid-state drives in external disk storage
subsystems, and almost half (48%) use
solid-state storage technology as extended
cache, memory, or primary storage within
servers.
If we fast forward to today, we
find that flash storage is used
heavily in modern data centers.
The primary reason is the
increased number of
implementation options. More
organizations are using flash
technology to meet their
application requirements.
Mike Leone
Key Takeaways
Flash storage adoption has increased
in recent years, as organizations have
deployed it to support business
applications.
When flash or solid-state storage was first
introduced, its primary benefit was performance. A survey by ESG found that over one
third of respondents (36%) said improved
performance drove their organizations’ initial
deployment of solid-state storage. However,
early adoption was slow due to cost.
Today flash storage is used heavily in modern
data centers, due to the increased number of
implementation options. ESG discovered that
End user needs have driven the use of flash
storage on servers, closer to applications. An
ESG survey found that over half of respondents (52%) said OLTP business applications
are driving their organizations to deploy
solid-state storage. Application end users
always want enhanced performance, higher
efficiency, and a better application experience.
Flash storage technology can deliver on all
these dimensions.
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EXECUTIVE
S U M M A RY
Deploying Affordable, High Performance Hybrid
Flash Storage for Clustered SQL Server
NexGen’s PCIe flash is dramatically
faster than solid-state drives and its
unique QoS technology guarantees
predictable application performance.
Integrating solid-state drives (SSD) into
storage arrays can generate performance
gains on the back end. However, in many
cases, the technology is still bottlenecked by
traditional RAID and controller throughput.
NexGen addressed these challenges by using
flah placed on the PCIe bus providing consistent, best-in-class PCI flash performance. The
technology is up to 40 times faster than
traditional SSDs.
Vincent LaPaglia described the important
elements of NexGen’s product portfolio:
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NexGen N5 Hybrid Flash Array. The
NexGen N5 combines high performance
PCIe flash and efficient spindle storage
into a low-cost, high-performance storage
array.
NexGen N5 SPX Solutions. SPX combines the NexGen N5 with SanDisk
ioTurbine software. The result is an out-ofthe-box solution that can be used for
highly available applications like SQL
clustering and three-plus node virtualization.
NexGen’s unique differentiator is its QoS
(Quality of Service) technology. QoS technology guarantees predictable application performance. Two key benefits are:
1. Built-in QoS policies provision performance and the array handles the IO
prioritization. The NexGen software and
real-time data placement eliminate the
need to dedicate array resources for a
singular need. That is a major advantage
from an architecture, engineering, and
administration standpoint.
2. It is possible to guarantee performance
levels for many high-performance
application workloads. Within a QoS performance policy, a minimum IOPS and a
not-to-exceed latency can be guaranteed.
By designating different systems as
mission critical, business critical, and
non-critical, IT teams can assign storage
volumes to each and eliminate contention.
The NexGen secret sauce . . .
is the QoS technology. Our
Quality of Service technology
guarantees predictable
performance for applications by
prioritizing which workloads are
assigned to performance policies.
Vincent LaPaglia
IT teams can maximize SQL Server
performance through storage best
practices, including the use of flash.
SQL Server is different from file server
systems. As a result, unique attributes must
be considered when designing storage for
SQL Server. Michael Otey discussed five
storage challenges related to SQL Server:
1. Performance requirements. Today’s
users and applications have more intense
performance requirements than ever
before. As a result, it is essential to select
a storage subsystem technology that
meets the organization’s performance
needs.
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EXECUTIVE
S U M M A RY
Deploying Affordable, High Performance Hybrid
Flash Storage for Clustered SQL Server
2. Database and log files configuration.
With database servers, database and log
files have different purposes and a single
database may contain multiples of these
files. The configuration of database and
log files can have a significant impact on
SQL Server performance.
3. Data availability. It is important to design
for high data availability levels. This is as
important as performance. If users can’t
access a database, it doesn’t matter how
quickly it performs.
nism, performance takes a hit every time
the database has an AutoGrow operation.
Organizations should be proactive and
manually size their databases to minimize
the chance that AutoGrow will be invoked.
Using AutoShrink is not advised.
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Enable instant file initialization. This
avoids zeroing out allocated space. Instant
file initialization is set through a Windows
Server Policy.
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Size tempdb properly and store it on its
own drive. Tempdb is a SQL Server
global resource that is available to all
users. It contains internal database engine
objects such as joins, aggregations, XML
and LOB data, cursors, sorting, hashing,
and row versioning. Sizing tempdb is
essential to avoid AutoGrow. By default
tempdb is only around 8 megabytes, but it
can be resized using the ALTER DATABASE command. When SQL Server is
restarted, it sets tempdb to its last configured size.
4. Backup and restore. Organizations must
be able to back up and restore their
databases if disasters occur.
5. Efficiency. When it comes to storage, IT
teams strive to be as efficient as possible
and not spend more than is necessary.
These challenges can be addressed by
implementing several best practices:
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Segregate database and log files onto
separate drives. By default, SQL Server
puts both database and log files on the
same drive as the SQL Server binaries.
That is undesirable from a performance
perspective because all the I/O is funneled
through the same drive. A best practice is
to separate the data and log files. Since
log files get a lot of write activity, they
should be placed on fast writing drives,
such as RAID 1 or 10 drives. This approach
also provides data protection for log files
Enable AutoGrow, but don’t depend on
it. AutoGrow prevents databases from
shutting down if they hit their maximum
sizes. While this is a good safety mecha-
Ideally tempdb should be maintained on
its own RAID 10 or better drive. Flash
storage is an excellent solution for tempdb. The SQL Advisory Team recommends
that enterprise scale databases use one
data file per core for tempdb.
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Be aware of SANs’ physical implementation. SANs can be a good solution for
storing SQL user databases. They offer
high performance, scalability, high availability, clustering, snapshots, replication,
and disaster recovery. Since they have a
good reputation for data tiering, they are
suitable for larger databases. However, it
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EXECUTIVE
S U M M A RY
Deploying Affordable, High Performance Hybrid
Flash Storage for Clustered SQL Server
is important to understand the physical
implementation. Find out how LUNs are
configured and make sure all I/O isn’t
funneled through one LUN. By maintaining data files, log files, and tempdb on
different drives, it is possible to split out
I/O and maximize performance.
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Use flash to accelerate SQL Server
performance. CPUs have become faster
and memory has become cheaper. Disks,
however, haven’t gotten much faster. As a
result, I/O bottlenecks can occur. Since
flash is much faster than rotational disks,
it can help with performance. Consider
the following statistics:
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A 15K rpm SAS drive can offer about
150 to 200 MB/sec of sequential
throughput.
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A 6 Gbps SATA or SAS solid-state
drive can provide about 550 MB/sec of
sequential throughput or about
100,000 IOPS random read and write.
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PCIe flash offers about 2 GB/sec of
sequential throughput and 250,000
IOPS random read and write.
PCIe flash eliminates many of the traditional storage controller and protocol
bottlenecks. Unlike SSD drives, PCIe flash
doesn’t need to emulate what a disk
would look like. This results in better
performance and more efficient I/O.
PCIe flash isn’t a silver bullet, however.
It cannot fix incorrect sizing, lack of
memory, or slow queries. It is best for
heavy, random I/O activity. Flash storage
is well suited for data files, log files,
indexes, and tempdb. To maintain flash
drive performance, keep utilization slightly
below 75%.
Many times with powerful and
memory-rich systems, disks
become the bottleneck. Flash
technology is a simpler answer
than implementing a SAN. Flash
storage can be dedicated to SQL
Server and provide much better
performance.
Michael Otey
ESG found that NexGen’s end-to-end
flash storage solution significantly
improved performance in SQL Server
clustered environments.
ESG recently conducted a lab validation that
simulated real-world OLTP workloads running
on a SQL Server cluster. The tests measured
IOPS, latency, and transactions per second.
Three storage scenarios were modeled:
1. Traditional. This included a SAN attached
array with SAS hard drives and no flash.
2. NexGen. This included a SAN attached
hybrid array with SAS drives and PCIe
flash.
3. NexGen SPX. This included an end-toend flash hybrid storage solution using
PCIe flash and ioTurbine software in a pair
of servers, as well as a SAN attached
NexGen array with PCIe flash and SAS
hard drives.
The first phase of testing measured the total
achievable IOPS and average latency from a
simulated OLTP workload. Mike Leone described the key takeaways:
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EXECUTIVE
S U M M A RY
Deploying Affordable, High Performance Hybrid
Flash Storage for Clustered SQL Server
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From an IOPS standpoint, NexGen and
NexGen SPX provided a 4 to 5.5 times
performance improvement over traditional SAN. The traditional SAN architecture peaked at little more than 17,000 IOPS,
while NexGen and NexGen SPX peaked at
around 69,000 and 93,000 respectively.
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Latency analysis showed that NexGen
delivered a significant increase in
average response time. When compared
to a traditional SAN, NexGen offered 4.2
times faster response times, while NexGen SPX provided a 6 times improvement
(see chart below). The NexGen solutions
increase productivity and customer
satisfaction, as end users demand faster,
more responsive application experiences.
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Under concurrent user loads, the
NexGen solutions supported many
more transactions per second than
traditional SANs. Using an SQL Server
OLTP simulation, the number of transactions per second was measured as the
number of concurrent users increased
from 2 to 72. NexGen supported 9 times
the number of transactions per second as
traditional SANs, while NexGen SPX
supported 10 times the number of transactions per second.
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Moving flash storage closer to where
applications reside creates a performance boost. Testing found that NexGen
SPX boosted performance boost for the
IOPS associated with applications. By
offloading IOPS to the server-based flash
storage, more array IOPS can service
additional SQL Server workloads. This is
important when multiple mission-critical
applications are running on the same
underlying storage subsystems.
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EXECUTIVE
S U M M A RY
Deploying Affordable, High Performance Hybrid
Flash Storage for Clustered SQL Server
By delivering enhanced database
application performance, NexGen
PCIe flash solutions reduce IT costs
and improve business operations.
Improving application performance is an
important objective for IT administrators. This
is especially true for mission-critical database
applications that support business operations.
Performance problems can lead to decreased
productivity, unhappy customers, and lost
revenues.
Unfortunately, as more diverse workloads are
added to the IT infrastructure and leverage the
same underlying storage infrastructure, I/O
bottlenecks emerge. Usually, IT admins
over-purchase and over-provision storage,
which adds complexity to the system. In
addition, this approach is less appealing as IT
budgets shrink.
By placing PCIe flash at the right place and
the right time, mission-critical applications
experience a significant performance boost.
This is a cost-effective way to increase storage infrastructure efficiency. NexGen hybrid
flash arrays enable higher application density,
greater efficiency, and an improved user
experience.
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EXECUTIVE
S U M M A RY
Deploying Affordable, High Performance Hybrid
Flash Storage for Clustered SQL Server
Biographies
Michael Otey
Vincent LaPaglia
Senior Technical Director, SQL Server Pro
Storage Engineer - Technical Marketing,
NexGen
Michael Otey is senior technical director for
Windows IT Pro and SQL Server Pro and is
president of TECA, a technical writing, softwaredevelopment and consulting company in Portland,
Oregon. Michael covers the topics of SQL Server,
Windows Server, VMware vSphere, virtualization,
PowerShell and .NET development. Michael
performs hardware and software product reviews
for the Windows IT Pro labs. He does frequent
webcasts, is a presenter at IT/Dev Connections and
other conferences and has written several books
on SQL Server and .NET development.
Vincent LaPaglia has 18 years in the IT industry
with 12+ years of storage architecture, design and
implementation experience. Proficient in a wide
range of storage technologies, as both an end-user
and as a consultant, he is a graduate of Syracuse
University and currently makes his home in
Colorado. He joined NexGen last year as a Senior
Storage Engineer.
Mike Leone
Lead Lab Analyst, ESG
Enterprise Strategy Group is an IT analyst and
strategic consulting firm anchored in end-user
market research and hands-on testing. Mike
Leone, a lead lab analyst, works in one of ESG’s
major practices, ESG Lab, which provides in-depth
testing and analysis of IT technology and products, using methods that simulate or recreate
real-world environments.
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