Server redundancy with identical hardware and disk swapping?
Posted on 2006-04-11
Theorectically, if I have 3 identical hardware platforms (motherboard, RAID controller, RAM, NIC etc.), is it possible to shut down the systems, swap out the hard disks (in this case 2 x RAID1), restart and the OS does not care (it will boot as normal)???
The reason I ask... I am thinking about a cheap hardware disaster recovery solution for an SBS 2003 and Windows Server 2003. I was thinking about ordering 3 identical hardware platforms, and installing on the 1st an SBS 2003 (Application server), on the 2nd a Windows 2003 Server (Fileserver) and the 3rd a Windows XP or another Windows 2003 Server (Backup server).
The only hardware difference between all would be that the Backup server would have more disk space (enough to backup the application & file server using disk to disk backup software).
In an event of a hardware failure on either the 1st or 2nd servers (motherboard, controller...), I could simply shut the relevant system and the Backup server, remove all disks from the Backup server, plug the disks from the relevant server into the Backup server, reboot and the OS would run as normal. I could then repair the 'broken' hardware in peace, my users are up and running quickly and the only services that don't run until the repair is over are those on the Backup server.
Does my theory have any holes? Is this a solution which would work and I could rely on? Are there cheap alternatives I have not thought of?
Thanks for your comments.