If you're thinking about deploying Microsoft System Center Data Protection Manager (DPM) to help with your back-up, you need to take into account that certain servers cannot store the data that DPM will be protecting.
Data Protection Manager protects your data by using an agent to monitor changes to the data. The catch is that the agent is a requirement, and it won't work on just any server.
If your data is stored on a server running Windows 2000 with Service Pack 4 or higher, or if it's stored on a Windows 2003 Server, you shouldn't have any problems. But if your data is stored on an Windows NT, Unix, Linux or NetWare server, you're out of luck. Since the DPM agent is not compatible with these types of servers, you cannot use DPM to protect the data they contain.
The same thing goes for network-attached storage (NAS). Data Protection Manager cannot protect data stored on a NAS server. However, Windows Storage Server may be an exception, since it is based on Windows Server 2003 code and may possibly support DPM. (Note: I have not been able to locate any documentation that confirms or denies this.)
Microsoft System Center Data Protection Manager: Reasons for server issues
Now let's talk about the server itself. There are stringent requirements for the server. Microsoft System Center Data Protection Manager requires the server to be running Windows Server 2003 with Service Pack 1 or higher (the 64-bit edition of Windows Server 2003 is not currently). The server must also have a minimum of two hard drives (either individual drives or arrays defined as a volume).
One of these drives is reserved for the Windows operating system and for the DPM system files. The other drive (and any additional drives you might want to use) are reserved for backing up data. You cannot store anything else on the drives used to back up the data.
The server's role is also important. The server cannot be a domain controller, but must be a member of a domain. Likewise, you cannot run any applications on the DP server other than DPM itself and standard applications such as antivirus software.
Microsoft System Center Data Protection Manager has some pretty hefty hardware requirements, and that's without taking into account the fact that Microsoft has traditionally been notorious for understating the hardware recommendations for its software. Microsoft recommends a server with a 1 GHz or faster processor, 1 GB of RAM, and disk space that is two to three times the size of the protected data.
Personally, I think Microsoft's recommendations might be a tad optimistic. I have not tried running DPM on a computer with a 1 GHz CPU, but I know it runs smoothly on my 3.2 GHz Pentium 4 server. I initially tried running Data Protection Manager with 1 GB of RAM. Microsoft System Center Data Protection Manager functioned flawlessly, but the user interface was a little slow. Giving the server another gigabyte of memory helped the speed issue.
Microsoft System Center Data Protection Manager: Reasons for disk space issues
Now for the disk space issue. Having a store available that is two to three times the size of the data that you are protecting is realistic, but you need to consider some other issues before deciding how much disk space to purchase.
One issue is that DPM stores multiple versions of each protected file. Suppose you make a change to a Word document. Microsoft System Center Data Protection Manager keeps the original version of the file on hand along with the new version. DPM only records the bytes that have changed in the new version rather than recording the whole file so that it can save disk space, but frequently changing files still tends to consume a lot of space. The point is, you want to have enough free disk space that you can maintain a month's worth of file changes. Microsoft System Center Data Protection Manager will work with less disk space, but the less disk space you have, the fewer file versions it maintains.
Another thing to consider: You shouldn't base your estimate on the amount of data you're protecting today. You will be protecting more data tomorrow, and you need to plan for that growth. I recommend estimating how much data you will have on hand a year from now and planning your disk space requirements based on that figure rather than on the size of your current data store.
One last issue regarding disk space is the requirement for two hard drives. Earlier I mentioned that one hard drive was reserved for the Windows operating system and for the DPM system files. That doesn't mean you can get away with using a small hard drive as the system drive. As I've said, it is important that you perform tape backups against your Microsoft System Center Data Protection Manager server. But to do so, your server's system drive must have enough room for DPM-aware backup software and to store temporary copies of the DPM and the report database.
Microsoft recommends that your system drive contain free space equal to at least double the size of these databases. That's not as bad as it sounds. Granted I have a small office, but right now my databases amount to about 40 MB and I am protecting roughly 160 GB of data. However, most of this data is static; organizations with lots of constantly changing data can probably expect much larger databases.
As you can see, it is important to plan out your DPM server prior to actually deploying it.
Microsoft System Center Data Protection Manager Fast Guide
Introduction
Verifying Data Protection Manager status
Server plays key role in Data Protection Manager deployment
Why Data Protection Manager is replacing disk-to-tape backups
Troubleshooting Data Protection Manager warning message
Measuring the impact of Data Protection Manager 2006
Storage pool savvy helps admins optimize Data Protection Manager
Watch for unsupported data types in Data Protection Manager
Protecting servers with Data Protection Manager
About the author:
Brien M. Posey, MCSE, is a Microsoft Most Valuable Professional for his work with Windows 2000 Server and IIS. He has served as CIO for a nationwide chain of hospitals and was once in charge of IT security for Fort Knox. He writes regularly for SearchWinComputing.com and other TechTarget sites.
