Getting the most out of disk-based replication

To put this into context, the report claims that we have already generated enough data to stretch to the sun and back 12 times, or to put another way, this digital universe equals approximately three million times the information in all the books ever written.

No matter how one looks at it, the implications are clear; we need our data. Not only are more of us generating more data - either as individuals or as organisations, but we are also replicating that data. Replication, or the copying of information to multiple systems, has been practiced for at least a decade. It frees up database availability and allows peer-to-peer access. The need for replication is also driven by compliance with government legislation and industry regulations as well as the shift towards globalisation.

Another factor, and perhaps one of the original forces driving the increasing need for data replication is disaster recovery. Real-time back up of databases to servers that are not affected by a specific event can make it possible to quickly switch users over to the server, eliminating the potential impact of an event and making a disaster less of a crisis.

Selecting the right solution

Data proliferation and the need for shorter back up times in the era of 24/7 business and Software as a Service, is leading storage administrators to find a balance between reliable data management and the pressures of cost and compliance for their organisation. The ability to recover large volumes of data within an acceptable timeframe is proving to be a major challenge for businesses.

The goal remains that of finding the most efficient and effective route to replicate data, but these points have to be considered in context of the specific needs of the organisation. Data replication is not just about networking but also is one that is affected by, and in turn affects, operations and applications. In selecting a solution, all of these elements need to be considered and balanced against each other.

Another major problem that storage administrators have to grapple with is that data is growing rapidly and is widely distributed in branch offices, remote sites and regional data centers. These remote locations can lead to the rise of silos of data because there may not be enough network bandwidth to let users move data easily and quickly between locations.

Multiple sites lead to a management challenge because they can require different levels of IT expertise. Fore example, smaller branches may not have a dedicated IT team on site for example. Storage vendors need to address the issues of eliminating redundant data and improving the utilisation of disk resources and data transport networks.

Approaches to Replication

Replication can be understood as being either synchronous or asynchronous. Put simply, synchronous replication uses a two-phase process meaning that when an update to the master database is processed it connects to all of the other slave systems and then updates then simultaneously. A disadvantage of this approach is that network downtime can be problematic. If one of the slaves is not available, the update doesn’t happen, potentially locking applications and freezing business.

Asynchronous replication can be either periodic of aperiodic (at set times or when needed). In this approach a replication engine tracks all updates and then ensures all systems are up to date. In the event of a network failure, the engine will keep on trying until the update is complete.

Data Duplication

Enterprise Strategy Group is convinced that eliminating data redundancy will be one of the most important technologies for all tiers of storage. Likewise The Taneja Group says this core technology can help fuel a range of new offerings in the backup and archival spaces.

De-duplication is powerful technology that can change the economics of the way that backup and archive data is stored on disk and moved over networks.

Quantum’s Offering

Data de-duplication is a technology that’s here to stay because the benefits are so powerful. Storage space is at an all-time premium and shrinking the size of the stored data volumes seems to be one of the few options left. Storage vendors need to allow end users to take advantage of new technologies such as data de-duplication. Users need to be vigilant about selecting the right data management solution for their needs. In response to this Quantum Corp. (NYSE:QTM), the leading global specialist in backup, recovery and archive, recently launched its first disk-based backup solutions incorporating data de-duplication and replication technologies: the DXi3500 and DXi5500 appliances.

By eliminating redundant data, the DXi-Series appliances allow users in midrange and data centre environments to retain 10 to 50 times more backup data on fast recovery disk and cost-effectively store data for months instead of days. Data de-duplication technology also allows Quantum’s appliances to provide WAN-based remote replication of backup data as a practical tool for disaster recovery between distributed sites such as data centers and regional offices. Quantum designed the DXi-Series to be easily installed and managed in a wide range of IT environments, and the company’s long-standing expertise in backup, recovery and archive solutions makes it uniquely positioned to meet customers' disk-based backup needs within this broader storage context.

Since completing its acquisition of ADIC in August 2006, Quantum has combined key technologies from both companies in an integrated software layer that is part of the DXi-Series solution. This encompasses Quantum’s patented data de-duplication technology and other enhanced functionality, providing such advantages as best-in-class performance of up to 800 GB/hour and interface flexibility between NAS and virtual tape libraries (VTL).

Heidi Biggar, analyst with the Enterprise Strategy Group, said: "Data de-duplication is a powerful technology, bringing real and immediate value to end users. With the introduction of its DXi-Series, Quantum adds data de-duplication to its disk-based portfolio. Combine that with in-line hardware compression, asynchronous replication, and onboard monitoring and diagnostic tools, and Quantum's got a powerful message.”

As stated previously, conventional disk storage cannot provide enough cost-effective capacity to let users retain more than a few days of backup data, limiting the benefits disk provides. Additionally, the amount of backup data in distributed sites and cost of bandwidth have prevented disk-based remote replication from being a viable solution, leaving data at risk in the event of a site loss or other localised threat. Quantum’s DXi3500 and DXi5500 address these issues with a strong appliance-based backup and replication solution that further expands the company’s disk-based backup portfolio.

Moreover, Quantum’s DXi-Series significantly increases the power of disk to support backup, data retention, and disaster recovery planning, while delivering the industry-leading performance that has long been a key differentiator of our disk-based solutions. Quantum has global scale and the comprehensive experience in backup, recovery and archive to provide customers with the right combination of disk, replication and tape for their environment and evolving storage requirements.

Quantum DXi-Series Advantages

In addition to data de-duplication, Quantum’s integrated software layer includes a high performance embedded file-system, in-line data compression, asynchronous replication, interface flexibility, and built-in monitoring, alerting and diagnostic tools. This integrated software layer not only provides a key advantage for the DXi3500 and DXi5500 appliances but also offers an extensible foundation for future intelligent backup, recovery and archive solutions that will improve data protection for a broad range of customer environments from remote offices to large enterprise data centers.

Quantum’s DXi-Series appliances provide a broad range of capacity options that deliver extended protection for data sets ranging from 250 GB to 11 TB in size. Assuming typical data mixes and standard backup methods, these appliances can offer up to 216 TB of disk-based retention capacity, using an average 20:1 de-duplication ratio – enough capacity to retain months of backups on disk for an 11 TB primary data set.

By delivering best-in-class performance, the DXi-Series also enables de-duplication to work more effectively for backing up enterprise data sets, optimising the amount of data that can be protected within a given time period. When compared to other data reduction products, DXi-Series appliances can protect the same amount of data in as little as half the time.

Easy to deploy and operate, the DXi3500 and DXi5500 are fully integrated appliances that can be presented to backup software as a NAS mount point (CIFS/NFS) or as a VTL with either Fibre Channel or iSCSI interconnect. Whether they appear as a standard NAS backup target or a familiar virtual tape interface, DXi-Series appliances are fully compatible with all leading backup applications and do not require that end users change their existing backup methodology or infrastructure.

As part of a comprehensive solutions set from Quantum, the DXi-Series is supported by a suite of global service offerings. These include Quantum StorageCare™ onsite warranty and StorageCare Guardian, Quantum’s proactive remote support solution all included as standard. Warranty extensions and upgrades as well as a full portfolio of professional installation and integration services are optional.