[CentOS] Booting Software RAID

Fri Jan 24 19:30:25 UTC 2014
Ljubomir Ljubojevic <centos at plnet.rs>

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