I know how RAID work and prevent data lost from disks failures. I want to know is possible way/how easy to recover data from unfunctioned remaining RAID disks due to RAID controller failure or whole system failure. Can I even simply attach one of the RAID 1 disk to the desktop system and read as simple as USB disk? I know getting data from the other RAID types won’t be that simple but is there a way without building the whole RAID system again. Thanks.
No, they mean that if the controller fails, you have to get a compatible controller, not just any controller. And that usually means getting another of the exact same controller. Hopefully they’re still available to buy somewhere. And hopefully it’s got a matching firmware version.
But if you’re using mdraid? Yeah just slap those drives on any disk controller and bring it up in the OS, no problem.