Question: > 
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> [Move raided hard drives between identical servers, preserving data](https://serverfault.com/questions/474456/move-raided-hard-drives-between-identical-servers-preserving-data) 
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I'm a server beginner working with a Sun x4600 and an IBM x3650. In the event that one of them dies, I want to have a plan for removing the hard drives from the dead server and hot-swapping them into the other with minimal downtime.

In a series of attempted practice runs (these servers are not in production use yet), I discovered that this is a lot harder than I had assumed it would be. The receiving raid controller doesn't autodetect new drives. To make it actually expose the new drives to the operating system always seems to require a reboot and reconfiguration in the raid controller's bios, where you have to "initialize" the new drives before it will recognize them as a raid array. This is not acceptable because it wipes precious data from the drives!

How do others handle this problem? How do you hotswap raided hard drives from a dead server with a different raid controller to a live server without destroying the data on them? Is it even possible?

So far it seems like the best I could do in that scenario is send the hard drives from the dead server to a data recovery service (because apparently raid arrays are not portable at all unless the raid controller happens to be exactly the same, so popping them into another server to recover the data won't work), have blank drives ready for another server and transfer backups onto them until I have a new server to replace the dead one. That can't be right, there must be a better way, right?

I would settle for getting a server to use a solitary hard drives (without the stupid raid controller wiping the data on it) that used to be in a raid 1 array.

Answer: 
Different RAID controllers? All bets are off. You *may* be able to get it to work with very closely-related cards of the same lineage, same firmware, etc., but it's highly unlikely that this is going to be supported by your hardware vendor.

Honestly, this is where a well-implemented and well-tested backup regimen comes into play. You don't need to muck about with swapping drives between disparate hardware - just restore onto the new machine and you're back up and running.
As you have already mentioned, different RAID controllers store metadata about the RAID arrays in different and incompatible ways.

Some OS's provide software RAID. Linux, for example, has mdraid, which runs in the kernel and is very mature and stable. It is fairly easy to re-assemble an mdraid array in any recent Linux box.

Of course, you lose the benefits of your RAID controler (e.g., cache, and probably I/O speed).

Linux is an example here. I think you have similar features in many other mainstream OS's (\*BSDs, modern Windows Servers, OpenSolaris, maybe IllumOS).