The System i-focused high availability and disaster recovery space has been roiling in a stormy sea of change; and now, with IBM's unification of Systems p and i into the Power Systems lineup — not to mention IBM's hot new PowerHA brand — the market is confusing at best.

Is it just a hardware mirroring or logical replication decision? What about IBM's Capacity BackUp Editions in a PowerHA world and the rise of storage area networks? And since Power Systems support AIX, IBM i, and Linux, what gives with PowerHA's multiple versions?

For IBM i pros who already manage their high availability (HA) and disaster recovery (DR) strategies, none of these questions are particularly confusing. Still, for those who have previously rejected robust HA and DR solutions as being too expensive or unnecessary, the tide is changing with new business requirements and applications that need to be ready to run in the middle of the night.

First, a Wicked Fast History

Not so long ago, there were three main players in the System i backup, recovery, and availability space: DataMirror, Lakeview Technology, and Vision Solutions. Their solutions were complex and expensive and geared toward larger businesses that had intense, 24/7 needs that justified the implementation, training, and support. Over the years, the big three saturated the market until iTera burst onto the scene with a simplified, cheaper — and for many smaller businesses — just as effective solution. iTera did what the others couldn't do: find new accounts by cracking the SMB nut.

Then, with some private equity help, Vision acquired iTera before turning and snapping up longtime rival Lakeview. As if that didn't add enough shake to the industry, IBM cut a check for DataMirror. And let's not forget the rise of Maximum Availability from the land down under. Though a smaller player, the company has been exploiting the increasing power of IBM i remote journaling with its affordable *noMAX suite of solutions. At the same time, other companies have been adding related products, including Quick-EDD's line of HA/DR solutions, VAULT400's online backup service, LXI's data vaulting backup and recovery solutions, Shield Advanced Solutions' Receiver Apply Program, and Bug Busters Software Engineering's RSF-HA, among others.

Three Basic Technologies

When it comes to HA and DR recovery choices for the i, there are three fundamental technology types: operating system-based solutions, storage-based solutions, and logical replication-based solutions.

Operating system-based solutions use switched independent auxiliary storage pools (IASPs) to provide data redundancy by letting you isolate applications and business data on a disk. The most common of these solutions is a switched disk or switched IASP cluster, where an IASP can be switched between two IBM i LPARs during planned or unplanned downtime. Then there's cross-site mirroring (XSM) with geographic mirroring provided by IBM i (and i5/OS). XSM provides continuous replication from one IASP to a duplicate IASP at a remote location.

With storage-based solutions, the main idea is to use storage area network (SAN) copy services to create a FlashCopy snapshot, or use Metro Mirror for local replication and global mirroring for asynchronous replication (across long distances). And by SAN, IBM means the DS6000 or DS8000.

Logical replication solutions based on IBM i's remote journaling features have been around for years and are typically found in IBM's iCluster (formerly via DataMirror), Vision Solutions' (ORION, Echo2, and MIMIX) products, and Maximum Availability's *noMAX.

The Rise of PowerHA

PowerHA is the renaming of existing IBM HA-related technologies so the moniker can span the Power Systems brand with a single product naming scheme that's immediately identifiable. So while PowerHA for i is basically the new name for IBM's High Availability Solution Manager (a.k.a. HASM), most everyone has to admit that "PowerHA for i" is an improvement. On the AIX side, PowerHA for AIX replaces IBM's High Availability Cluster Multi-Processing (HACMP). The PowerHA solutions are similar but use different OS-based components to get the job done.

"Obviously, our main goal is to provide a range of availability solutions for IBM i, as well as our AIX customers. We do indeed have a very good set of solutions on both the AIX and the i side," says Ian Jarman, IBM's manager of Power Systems software, noting that traditional HA solutions have been characterized by software-based logical replication.

"At the same time, if you look at availability solutions in other markets, there's been a trend toward disk clustering, in particular for customers who are moving toward SAN-based solutions. So if you look at the Unix marketplace, typically the resiliency solutions are provided with hardware disk-clustering solutions," he explains.

"One of the reasons it's important for us to have PowerHA on i is that we have increasing numbers of customers who, in the data center, have both AIX and i solutions, and they have a strategy to consolidate their storage. When they do consolidate their storage, for example, on a DS8000, they look at how they can standardize their resiliency strategy just like they've standardized their storage virtualization strategy," Jarman says.

Though PowerHA for AIX focuses on logical volume management, PowerHA for i is focused on a similar disk-clustering structure but uses i terms like IASPs.

"They're not interchangeable, but they have the same goal, and both integrate well with Metro Mirror and FlashCopy," Jarman says.

CBU Editions Still Working Hard

IBM's popular Capacity BackUp (CBU) Editions are still selling well, IBM says. Big Blue initiated the CBU concept to help customers deploying logical replication solutions by providing a backup server where customers could transfer licenses from primary servers. CBUs offer more flexibility than a secondary server so that customers can add production workloads to the backup server, depending on their licenses.

"CBU editions let you adapt the solution over time. So if you started out with a simple disaster recovery solution, you could add processors to the backup server and create a high availability server," Jarman says. "The CBU can be used with logical replication solutions from Vision, IBM, and Maximum Availability, as well as disk-clustering solutions like PowerHA."

The Hardworking — and Flexible — Standby

When Vision Solutions, for example, talks to new customers, the company tries to sort through whether logical replication or hardware mirroring would be the best choice for a customer's circumstances.

"There are advantages and disadvantages on both sides, and it tends to come down to what each customer is looking for," says Bill Hammond, director of product marketing for Vision Solutions. "We think that logical replication is the more flexible solution in a majority of cases.

"It's not that hardware mirroring is a bad solution; we just think we are the better fit most of the time," he adds.

However, he notes that Vision also sees a growing number of customers looking at the inventory of solutions and not making a single-product decision. "Some want to use hardware mirroring when they are dealing with data in the data center with two HA servers — and also use logical replication to get their data off site. It's not always an either-or decision," he explains.

One of the good things about PowerHA, Hammond says, is that IBM's sales force is out and about raising awareness of hardware mirroring, and that effort has had the side effect of educating the HA market, "Which is a good thing," Hammond adds.

"One of the key drivers, historically, with our software, has always been that people have been able to do something with the second copy of the data they created — like business intelligence reporting," Hammond explains. "So we could talk about the very quick ROI you can get by being able to do something else with the second copy of the data. With hardware mirroring, the second copy is locked, and you can't use it unless you actually switch to it."

Big Broad Trends

"What we've seen over the last few years as the complexity to run and manage came down, and as the cost came down, there's been a whole new category of buyer — they don't tend to be as vertically focused a group of people," Hammond says. "It used to be financial services, logistics . . . and now we're seeing a lot of health care, retail, county governments . . . ."

IBM's Jarman has been noticing the same market-broadening activity.

"There's a growing trend to deploy HA solutions across the board. Ten years ago, HA was a solution that was largely just in large enterprises. But in the last five years, the price has come down significantly. The simplicity of deploying these solutions means that even small and midsized customers can implement them, and that has led to a significant trend in expanding HA into SMB," Jarman says.

"Secondly, there's been a trend toward disk clustering, and this is due to the use of SANs with our larger customers," he adds, though he notes that most of IBM's smaller customers aren't looking at SAN-based solutions and more typically install logical replication-based solutions — again, most often from Vision, Maximum Availability, and IBM.

Incidentally, IBM resells one product from Vision Solutions, Cluster1, which is a bridge product for customers who want to deploy PowerHA in conjunction with other Vision products like ORION or MIMIX.

While most of IBM's customers have a good backup and recovery strategy, Jarman says more and more IBM i-based organizations are being asked to make their applications available 24 hours a day, especially as they move to the web. "So their backup strategies of the past may not be appropriate in today's changing landscape," Jarman adds.

What's most interesting, however, is that despite the consolidation of the heavyweight HA/DR solution providers in the IBM i world, there remains a variety of robust ways to achieve various levels of availability.

Chris Maxcer is news editor of System iNEWS. "On a side note, now that the dust has settled from the HA acquisitions, Vision is reporting that there’s a lot less 'contract trading' going on," Chris says. "So instead of focusing on how to poach customers from competitors, the HA vendors are reaching out to SMBs, and may be doing more good for the System i world than ever before."