On 01/24/2014 07:32 PM, John R Pierce wrote: > On 1/24/2014 10:11 AM, Les Mikesell wrote: >> On Fri, Jan 24, 2014 at 11:25 AM, Matt<matt.mailinglists at gmail.com> wrote: >>>>>> >>>> I am guessing this is saying its present on both? I did nothing to >>>> copy it there so it must have done it during the centos 6.x install >>>> process. >> I think the 6.x installers try to do it for you on both drives - but >> whether it actually works or not may depend on the type of failure and >> what the bios does to the disk mapping as a result. In any case it >> is a good idea to know how to recover from a rescue-mode boot of the >> install ISO. > > 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). And if disks can be hot-swapped then only concern is that GRUB and /boot survive the crash. -- Ljubomir Ljubojevic (Love is in the Air) PL Computers Serbia, Europe StarOS, Mikrotik and CentOS/RHEL/Linux consultant