On Fri, Jan 24, 2014 at 1:30 PM, Ljubomir Ljubojevic <centos at plnet.rs> wrote: >> >> and, even if you have the boot loader on both drives, there's no >> guarantee your BIOS will boot from the 2nd one. Disks can partially >> fail in nasty ways that might allow the already-running system to stay >> up on the other half of the mirror, but when the drive is 'tested' >> during power up boot sequence, it could hang the system. >> > > True, but forwarding of root mail to admins e-mail address will warn > about crash of mirror, so physical intervention of choice can be made. I > think manual change in BIOS is of little consequence if system will boot > off of surviving disk(s). Doesn't grub need to know the bios disk id for subsequent stages of the boot and where to find the root filesystem? I think it matters whether or not bios remaps your 2nd drive to the first id. > And if disks can be hot-swapped then only concern is that GRUB and /boot > survive the crash. And if you know how to do a rescue-mode boot and reinstall grub, you can fix that too. -- Les Mikesell lesmikesell at gmail.com