Organizations today are more aware than ever of how their business can be immediately impacted by the interruption of access to critical applications and data.

However, traditional data access solutions implemented by many large organizations to provide near-continuous uptime and access to data often exceed ever diminishing budgets due to their complexity and sophistication, and can leave small and medium-sized businesses (SMBs) in particular exposed to catastrophic outages and data loss.

High Availability (HA) is a term used to describe the system design protocol and associated implementation that ensures operational continuity during a given measurement period. It can be quantified in percentages approaching 100%, which represents the ideal: total availability and complete access to all data and resources at all times. Typically numbers that represent close to “five nines” availability (99.999% available) are the most sought-after.

A High Availability configuration of storage appliances can be implemented in storage area networks (SANs) to provide continuous operation in the face of a wide variety of threats and potential disasters. Thanks to StorTrends iTX data storage software, High Availability is now more accessible than ever to SMB users - without terrific investments in equipment, time and energy.

Mirrored Servers for High Availability in StorTrends iTX

StorTrends iTX, the data storage software that comes pre-installed on all StorTrends storage appliances from American Megatrends, employs a “mirrored server” approach for its High Availability implementation.

In this model, two independent storage servers are coupled inside the same SAN fabric and data is mirrored between them. Any data write that happens to the disks of one unit is mirrored online to the other unit.

From the hardware perspective, this configuration will also often take advantage of COTS units, a definite positive mark in its favor. The disadvantage of this architecture, however, is its requirement for twice the number of hard disks, which makes it much more expensive in terms of its hardware cost and adds to the space footprint and electrical power requirements.

From the reliability perspective, the upsides of this implementation are also nothing short of phenomenal. Duplication of the disk subsystem, which is independently protected by RAID, enhances the reliability by orders of magnitude. Moreover, the two units are typically housed in different buildings, isolating them from identical environmental and stress characteristics as experienced with the first two solutions. Basically, there is no shared component and as such they do not suffer from a shared risk.

IP Virtualization

StorTrends storage appliances using StorTrends iTX 2.7.1030 version 3.x take advantage of a new, improved IP virtualization mechanism to implement High Availability. The advantage with IP virtualization is that there is no dependency on the client side, unlike multipathing, and therefore no special module that has to be loaded on client systems. This makes the implementation both OS and platform agnostic. It also allows StorTrends to deliver a robust HA solution across the board, even for deployments that use application server virtualization or application server clustering.

In a mirrored server HA environment, the primary StorTrends appliance assumes the responsibility of mirroring data to the secondary unit, including re-syncing as and when needed. To do so, the client server first logs in to the volumes in the primary storage server using a virtual IP address.

Configuration and Management of HA Nodes with StorTrends iTX

Configuring and managing High Availability in StorTrends iTX is intuitive and simple. StorTrends iTX makes it easy by giving users the option of configuring via ManageTrends™, which is the Web-based management interface for StorTrends iTX, or by using Command Line Interface (CLI) commands.

Note that HA configuration for SAN users requires the use of two StorTrends nodes setup for Active/Active High Availability configuration; the HA Configuration Wizard in ManageTrends helps to quickly setup the HA pair. Once the mirrored volume configuration is setup, Resource Groups are created to control the I/O flow from the clients.

Want to Learn More?

For more information about the OS-agnostic, platform-independent High Availability capability featured in StorTrends Data Storage appliances, log in to download the whitepaper from our Storage Library. If you haven’t already registered on StorTrends.com, click here to register and get started accessing detailed information on StorTrends products, including whitepapers, technical briefs, case studies, and more.