DPM aims to keep off the data weight

14.04.2005
Von Oliver Rist

They call it managing my weight. I call it bouncing up and down the fat-boy meter due to variables such as season, adult ADD, work stress, and emotional fruit loopiness. Sometimes I grab real control for a few months and the weight drops like a rock. Then one or more of the variables decides to get kooky and I"m back on my way to looking like Oliver Platt. It"s quite similar to data bloat in a Windows network, actually.

You think you"ve got your data under control, and then something happens, such as a new business requirement or a new application. Next thing you know, your neat storage solution starts to fray around the edges, and before long it"s wearing XXL sweatpants again. Not so bad if you"ve got the spare disks, but hell to manage during a restore procedure.

Fortunately, at the Windows Server Technical Reviewers Workshop a month or so ago, various Microsoftees reintroduced me (under Kill by Bill NDA [non-disclosure agreement], of course) to Data Protection Server (which we"re all supposed to start calling DPM [Data Protection Manager]), slated for release sometime late this year or early next. Microsoft finally lifted NDA on this puppy last week, so I"m allowed to delve into it without having my car explode the next time I back out of the driveway.

DPM is Microsoft"s first stab at a distributed and disk-based backup-and-restore solution. Like other architectures of this type, DPM aims itself at designated Windows servers and keeps snapshot references at scheduled points. Should a restore be required, DPM restores assigned servers from multiple time points -- useful not only for getting a critical server back online but also for security and compliance.

Initially DPM will work with base Windows 2003 Server services such as Active Directory and DNS, and will work in conjunction with WSS (Windows Storage Server) so all you happy NAS users can drop DPM right on top of those WSS-based appliances. Microsoft has targeted Exchange Server and SQL Server as the next recipients of DPM"s graces, although it"s unclear whether that functionality will be ready in time for the initial shipping version.

Overall, DPM is an obvious step forward for Microsoft. IT administrators are becoming paranoid about the effects of new Microsoft code on their existing installations. Network security is more dangerous than Dodge City in the mid-1800s, and ever more business managers are making it known that maintaining uptime has to be an IT do-or-die mission. Disk-based recovery is fast recovery, and that"s exactly what all these factors have in common.

Of course, because it"s from Microsoft, DPM goes just so far and no further. What made me grind my teeth was when the Redmondian giving the demonstration replied to my question about DFS (distributed file system) with, "For the time being, DPM is not DFS-aware."

So it"s a distributed backup-and-restore solution that touts manageability from a central location as a key benefit, but it doesn"t understand or interact with the Windows DFS. So if you"re using DFS to replicate data between servers at distributed sites, you won"t be able to centralize those DPM servers. You"ll be able to see them from a central location, but you"ll need to have a DPM server or two at every site to make the system work.

OK, fast disk-based recovery would certainly be slowed down by a T1 or DSL pipe in the middle, but if I"m designing a tiered backup architecture, tying that into my distributed file system certainly would have been sexy. As it stands, DPM will monitor and back up eight servers in near proximity, and if you"re envisioning anything more enlightened, you"re looking at the next version.

And it"s not just the lack of DFS integration that bugs me; it"s the cost. Each one of these things is going to require its own server license, a necessarily speedy set of CPUs, and a storage system as fat as you can make it. And now you"ve got to buy multiple sets of these behemoths if your network spans more than one site. For larger companies the cost burden won"t be so glaring, but for the strapped small and midtier companies, it"s yet another check mark in the Microsoft Neglect column.

Then again, for all we know, Microsoft is readying a small-business DPM and just hasn"t told anybody yet.