One of the fundamental requirements for virtualizing applications is shared storage. Applications can move around to different servers as long as those servers have access to the storage with the application and its data. Typically, shared storage takes place over a storage network known as a SAN. However, SANs typically run into issues in a virtual environment, so organizations are currently looking for new options. Hyper-converged infrastructure is a solution that seems well-suited to address these issues.

1. The Problem withTraditional Shared Storage
One of the fundamental requirements for virtualizing applications is shared
storage. Applications can move around to different servers as long as those
servers have access to the storage with the application and its data. Typically,
shared storage takes place over a storage network known as a SAN.
However, SANs typically have issues in virtualized environments. The first
is providing consistent, reliable I/O performance where it is needed. As
different applications start, stop and process data, the load on the SAN varies
greatly. If a database starts a large job processing data, the SAN may become
overwhelmed, which will start impacting the performance of other applications
that are acting in a normal state. Applications that are performance-sensitive
are particularly susceptible to this issue, including databases (Oracle, Microsoft
SQL Server); applications and ERP systems based on databases (SAP, Oracle
Applications, Microsoft SharePoint, Microsoft Dynamics);VDI (VMware
and Citrix); and communications systems (Microsoft Exchange,VoIP).
In addition, as the number of applications in the environment grows, IT needs to
be able to scale out infrastructure seamlessly and quickly. Any time maintenance
is done on a SAN, the storage needs to go offline, leading to a disruption.
Another issue, especially in smaller environments such as remote sites, is the
reliability and complexity of SANs. When remote or regional locations (retail stores,
bank branches, manufacturing plants, call centers, distribution centers, healthcare
clinics, etc.) have applications on-site, IT needs to address issues with availability and
management of the infrastructure. In the simplest case, an office has two servers to
ensure high availability at the compute layer.
How Software-defined Storage
Enhances Hyper-converged Storage
ABOUTTHE AUTHOR
Sushant Rao is an expert in
the areas of virtualization,
cloud and software-
defined technologies
having worked for
companies such as
VMware, HP Software as
well as numerous startups.
Currently, Sushant leads
DataCore’s efforts around
product messaging,
competitive positioning
and overall GTM strategy.
To learn more visit:
www.datacore.com
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2. 2
”To provide consistent
high-performance, IT can
create application-specific
clusters. By running the
same type of application on
the cluster (e.g. databases),
IT is better able to manage
performance and identify/
resolve bottlenecks.”
- Sushant Rao
DataCore Software
However, the servers are connected to a SAN (typically a low-end storage array
and network connections), which is a single point of failure. If the SAN goes offline
for any reason, it doesn’t matter that there are two servers; the applications have
an outage, which disrupts the business. In addition, usually there isn’t any IT staff
on-site, so simplicity of management and reducing complexity are very important.
Due to the challenges of using SANs in a virtual environment, organizations
are currently looking for new options. Hyper-converged infrastructure
is a solution that seems well-suited to address these issues.
Hyper-Converged Systems for Consistent, Reliable Performance
To provide consistent high-performance, IT can create application-specific
clusters. By running the same type of application on the cluster (e.g.
databases), IT is better able to manage performance and identify/resolve
bottlenecks. In addition, to avoid the performance limitations of a SAN, hyper-
converged storage utilizes Direct-Attached Storage (DAS) within servers as
shared storage, moving data closer to the applications. This architecture
provides better I/O performance closer to the application (therefore creating
better response times), resulting in less complexity and lower cost.
RealWorld Use Case for Reliable Application Performance
Following is an example of how a hospital used DataCore Software’sVirtual
SAN (software to create a hyper-converged system) to achieve better and more
consistent application performance. The hospital had 12 physical servers running
its PBX system. The organization wanted to virtualize this application (into 12
VMs) but it was essential to provide the same level of reliable performance as the
physical servers since voice communication is vital in a hospital environment. The
hospital knew it wanted a dedicated cluster for the virtualized PBX application.
But, its IT staff wasn’t satisfied with their options, such asVMwareVirtual SAN,
which required a minimum of three physical servers (and later, they learned that
actually four servers were recommended). The consensus was that utilizing
three servers to run 12VMs was wasteful and unnecessarily expensive.
Instead, the hospital chose DataCore’sVirtual SAN software. This solution only
requires two servers for failover, which reduced costs by 33% at the onset. In
addition, DataCoreVirtual SAN uses adaptive RAM caching to accelerate
I/O. RAM is generally 10x faster than Flash storage, so the performance of the
virtualized PBX was “through the roof.” In addition, the RAM caching meant
that Flash storage was optional, further reducing costs for the hospital.
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3. 3
The last consideration was the ability to scale, with a converged architecture,
compute and memory scale with storage capacity. If more storage capacity
is needed, but additional compute / memory is NOT, then the options are less
than desirable. IT can either change the drives in the servers to offer higher
capacity or add another server. However, DataCoreVirtual SAN, with its
Integrated Storage Architecture, can utilize a centralized SAN to complement
the direct-attached storage inside the servers. This means that additional
storage capacity is made available from the central SAN and data resides on
the tier that best matches its performance requirement. For example, “hot”
data remains close to the server tier and “cold” data remains on the SAN. This
option provided the hospital with the ability to optimize application performance
and add greater flexibility to scale storage and compute/memory as needed.
Hyper-converged Systems for Regional Offices
For regional sites that need to run a mixture of workloads and make
the infrastructure highly available, the logical solution is to turn to local
storage in the servers into redundant shared storage, thereby increasing
availability. In addition, reducing the amount of hardware needed for
availability reduces the physical footprint of the infrastructure (which may
be constrained to a a small space, such as a closet at the site) as well as
the costs. Lastly, by combining compute, network and storage into one
infrastructure, the complexity of managing separate pieces is removed.
”DataCore Virtual SAN,
with its Integrated Storage
Architecture, can utilize a
centralized SAN to complement
the direct-attached storage
inside the servers. This
means that additional
storage capacity is made
available from the central
SAN and data resides on the
tier that best matches its
performance requirement.”
- Sushant Rao
DataCore Software
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4. For additional information, please visit www.datacore.com or email info@datacore.com
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02/15
RealWorld Use Case for Hyper-converged
Systems for Regional Offices
Another example of a company using DataCore’sVirtual SAN is a large restaurant
chain with over a thousand locations. The company runs a number of applications
on-site (point-of-sale, order scheduling, etc.) because it cannot have its restaurants
grind to a halt due to data center orWAN outages. With their key applications
running locally, the IT department needed to ensure that the on-site infrastructure
was highly available and easy to manage. However, many sites lacked space for
equipment, so there was also a need to drive down the physical size and cost of the
infrastructure. The IT department realized that hyper-converged infrastructure was
the right approach. Early on, they decided a software solution would be the best
option as it didn’t lock them into any particular hardware vendor and allowed them
to provide high-availability with only two servers. In addition, they needed a lower
cost virtualization platform, so the solution needed to support Microsoft Hyper-V.
The IT department evaluated many alternatives and decided that DataCoreVirtual
SAN was the right solution. The DataCore product synchronously mirrors data
between two servers for high availability (compared to three or four nodes for other
products), supports Microsoft’s Hyper-V (in addition toVMware vSphere) and runs on
standard x86 servers (giving a choice of server vendors). In addition, DataCoreVirtual
SAN accelerates I/O using adaptive RAM caching directly on the servers, which means
Flash storage is not needed, further reducing costs.The software also supports
auto-tiering, allowing a mix of flash and disk if even more performance is required.
By dramatically reducing costs, as well as the space needed for a highly available
infrastructure, DataCoreVirtual SAN is the ideal solution for remote and branch sites.
Bringing it all together with Software-defined Storage (SDS)
There is a downside to hyper-converged storage. Each deployment becomes a
separate storage system to manage and maintain.To ensure that yet another,
separate data island isn’t created with hyper-converged infrastructure, it needs
to be integrated into the overall storage infrastructure and management.
This is where DataCore’s Software-defined Storage platform comes in. By
augmenting hyper-converged infrastructure with the capacity advantages
and investments made in existing SANs, DataCore can scale storage capacity
and performance easily and efficiently. More importantly, the DataCore
SDS platform unifies all of the storage systems from different vendors
and provides one set of comprehensive storage services across the entire
storage infrastructure -- under a single pane of management -- so it is easy
to administer the storage infrastructure and unify separate data islands.
ABOUT DATACORE
DataCore is a leader
in software-defined
storage.The company’s
storage virtualization and
Virtual SAN solutions
empower organizations to
seamlessly manage and
scale their data storage
architectures, delivering
massive performance
gains at a fraction of
the cost of solutions
offered by legacy storage
hardware vendors. Backed
by 10,000 customer
sites around the world,
DataCore’s adaptive
and self-learning and
healing technology takes
the pain out of manual
processes and helps
deliver on the promise of
the new software defined
data center through
its hardware agnostic
architecture.
www.datacore.com
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