Take the 2-minute tour ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.

This is hypothetical question, but one I’m sure that someone must have encountered and/or given some thought to before.

Situation: Consider this, a small business is running an Active Directory domain and has two domain controllers which are located in their office. The domain controllers are both physical servers (no virtualisation).

A system state backup of the domain controllers is run every day.

The company suffers a disaster (a fire or flood) that damages their servers beyond repair.

The company would like to rebuild their domain controllers using the backups however they cannot get hold of the same make and model of servers (because they’re a few years old). This presents them with a problem because Active Directory is backed-up as part of the ‘system state’ which means it’s tightly coupled to the original hardware.

Summary: Unless a small business has the ability to host one domain controller offsite (to safeguard against a potential disaster that damages all the servers at their office) then at least one of their domain controllers must be virtualised in order to make the restore process hardware agnostic (thus not requiring them to buy the exact same model of server). Would you agree?

share|improve this question
    
I suppose I’m really considering practically as well as what’s technically possible. Because Active Directory is backed-up as part of the 'system state' (which is very much bound to the original hardware), you have to go to a reasonable amount of hassle to tweak things on your new hardware. Your objective is to get Active Directory going again, not to emulate the old server, so it’s a pity you have to waste time doing so. –  Fitzroy Sep 21 '12 at 15:55
add comment

2 Answers

No I do not agree. In fact, even a Win 2003 DC it is possible to restore to different hardware and salvage AD. Now, you probably want to get a fresh install of Windows up on another box after the restore to replicate AD to and then demote the restored box since it probably isn't the stablest of systems, but it works. Google "active directory backup and restore" and the first link is http://technet.microsoft.com/en-us/library/bb727048.aspx. Here is the section you need to pay attention to:

Considerations for restoring onto different hardware

It is possible to restore a domain controller onto different hardware. However, you should consider the following issues:

Different hardware abstraction layers (HALs). By default, the Hal.dll is not backed up as part of system state, however the Kernel32.dll is. Therefore, if you try to restore a backup onto a computer that requires a different HAL (for example, to support a multiprocessor environment) compatibility issues exist between the new HAL and the original Kernel32.dll. To overcome this incompatibility, manually copy the Hal.dll from the original computer and install it on the new computer. The limitation is that the new computer can use only a single processor.

Incompatible Boot.ini File. If you backup and restore the boot.ini file, you might have some incompatibility with your new hardware configuration, resulting in a failure to start. Before you restore it, ensure that the boot.ini file is correct for your new hardware environment.

Different Network or Video Cards. If your new hardware has a different video adapter or multiple network adapters, then uninstall them before you restore data. When you restart the computer; the normal Plug and Play functionality makes the necessary changes.

Disk Space and Partition Configuration. Partitions on the new computer must match those on the original computer. Specifically, all the drive mappings must be the same and the partition size must be at least equal to that on the original computer.

share|improve this answer
    
I had realised that through manual 'tweaks' it may be possible to recover to dissimilar hardware, however I did fail to find it officially documented, so thank you for pointing out that Technet article. I am in agreement with you when you say: "...you probably want to get a fresh install of Windows up on another box after the restore..." So whilst it's probably possible to restore to dissimilar hardware, it's not exactly the most desirable procedure. Microsoft haven't exactly made it a walk in the park. –  Fitzroy Sep 21 '12 at 15:16
add comment

Windows Server 2008 and later support bare metal restores to dissimilar hardware with the built-in backup utility. This is a non-issue.

share|improve this answer
    
Thank you for pointing that out - that is a fact I wasn't aware of, so I will research that further and comment appropriately. –  Fitzroy Sep 21 '12 at 15:17
    
This might be a good place to start :) –  MDMarra Sep 21 '12 at 15:19
    
you could invest in something like Shadow Protect shadowprotect.com that has a dedicated SBS version that can image and entire server to .spf format which is hardware independent. You could get two external hard disks one for week 1 and week 3 and one for week 2 and week 4, rotate the disks by taking one offsite. I do this every week, and have actually restored from a SP backup in a real situation. –  bettsy583 Sep 26 '12 at 7:14
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.