Bare-metal restores can be challenging. A little planning up front can save you a lot of headaches when performing a bare-metal restore. W. Curtis Preston, executive editor of the Storage Media Group answers common questions about bare metal restores in this Q&A. His answers are also available as an MP3 below.
Table of contents:
>> What is a bare metal restore?
>> Do you need specialized tools to perform a bare metal restore?
>> What are the biggest challenges when performing a bare metal restore?
>> What can you do to mitigate these challenges?
A typical restore just restores files, and a with a bare-metal restore, you are actually restoring to blank disk drives. So, either the operating system disk has gone south, or in the worst-case scenario you are actually restoring to a different system in the case of a fire or other disaster.
Absolutely. There are a number of technological challenges. First, if you are just restoring back to the same place and you lose the operating system disk, you need to be able to see the disk that you are restoring to without running on the disk that you are restoring to. The most common method is to boot off of some alternate media. Then you are running on a mini-Windows or a mini-Linux while you restore this other disk drive. Any product should be able to restore to bare metal with Intel-based hardware, but if a company is advertising a bare-metal restore product, it really should automate this process.
The second challenge is restoring to dissimilar hardware. Then, you have a whole different set of problems. You may be restoring to a SATA drive from what was a Fibre Channel drive. You may be restoring to a motherboard that has a completely different set of drivers.
The first is the same as with any restore: They've never done one before. A lot of people make the assumption "Well, I'm backing up the OS drive. So, I should be able to restore the OS drive." That's pretty much the biggest one. Other mistakes include a.) not testing it and b.) ignoring or not wanting to pay extra for functionality included with your data backup software.
Symantec NetBackup is a perfect example. BMR is now built into the base product but for a while it was an expensive add-on -- something like $2,500 a server. Now it's built in to the product, but you still have to click the little box. So, if you've never performed a bare=metal restore, and because you've never done it before and you didn't click the little box, well, that's a bad day for you when that happens.
There's a couple of things. The first thing I'm going to throw out there is virtualization, virtualization, and virtualization. This problem doesn't really exist in VMware, Hyper-V and Xen. There's a different set of problems; I'm not saying backup is easy in VMware land. It's not. But, the whole issue around dissimilar restores goes away because it's the same hypervisor everywhere. Also, there's built-in stuff to backup at the image level, so you can restore the entire VMDK and you are off and running.
Also, just play with the stuff. Try it out up front. Another important thing is to standardize. The more you can standardize on hardware the better. If you are one of these shops that just buys the latest, greatest, cheapest stuff and you expect it to work, that's the surefire way to make this problem very difficult.
Finally, if you go the imaging route you'll be a lot better off. You don't want to have to load the OS the old fashion way. That way you aren't really doing a restore you are just re-imaging the system.