While a fair few vendors now provide continuous data protection (CDP) as part of providing real-time data (file) replication and failover, their claim to provide low cost disaster recovery (DR) is somewhat exaggerated. But if the process is extended to cover the server operating system (physical and/or virtual) and applications, then this claim becomes more credible.
A full-blown DR involves mirroring the whole live system, hardware and software, to a remote location—but that is hugely costly. Using CDP to write out every system as well as file changes to a remote system via a WAN or across internet comes close to matching this at a fraction of the cost.
Most such products, however, do not deal with operating system or application changes, but one that does is Double-Take. Although the need to quickly recover the operating system should be rare—with operating system corruption rarer—this can occur; a system not totally recovered might not then run. So this facility reduces failover and recovery risks versus software that does not provide this.
Despite this, having a few extra ticks in the features box is not alone enough to set the world alight; another couple of elements are equally important. There is every need for the replication software itself to be super-reliable or recovery will be a hit-and-miss affair. Then it has to be easy-to-use or potential users will generally turn away from it. So Double-Take Software has spent time and effort addressing both of these. That approach seems to have been a major catalyst in bringing the company of the same name success.
"Our biggest asset is our reputation," Double-Take's CEO Dean Goodermote told me. "We have a very promotional customer base and we get many sales by word of mouth." So here is one acid test: the users themselves like it enough to tell others.
Emphasising this point, Goodermote said of the Double-Take product that the company tried for perfection and, while obviously this was not totally achieved, it was known for very high reliability. It was also non-intrusive to run and straightforward to install—and he described his own work-force as "a respected group of people."
There is, of course, some advanced technology behind the product's success, with its byte-level replication claimed as unique and versions covering Windows, virtualised (VMware) and Linux. The software is also well-suited to replication as part of re-configuring or upgrading the infrastructure. A fairly recent acquisition has led to an ability to do fast network booting of images from iSCSI disk to speed recovery, facilitate a low-cost software-only Storage Area Network (SAN) on the server, and boot images from desktops (taking the company into new market areas).
Yet I suspect it is more important to users that they have a hassle-free life without the fear that system failures might not be quickly recovered because of software flaws.
The method by which the software is now sold is also telling as it bucks the market trend through bundling annual maintenance and support with the software itself. This means the initial purchase price is a little higher. However, Double-Take's channel partners like the maintenance renewal rates after the first year soaring over the 90% mark (versus a typical 70% renewal level). This is not because service calls are frequently needed—rather the reverse—but because users want to keep using their software!
This licensing approach could deter potential customers if the software demonstrated anything other than the rock-solid reliability with high functionality suited to backup and DR regimes. As it is, it is helping maintain a healthy and predictable cash flow, as a useful hedge against the present difficult economic conditions.
In these straitened times, some vendors could learn a lesson or two from Double-Take about setting high and comprehensive development standards.
Goodermote hinted at future plans that will widen the scope of the software; but right now Double-Take looks to me to be positioned well enough.