[CentOS] Help finishing off Centos 7 RAID install

Wed Jan 9 20:02:40 UTC 2019
Gordon Messmer <gordon.messmer at gmail.com>

On 1/9/19 2:30 AM, Gary Stainburn wrote:
> 1) The big problem with this is that it is dependant on sda for booting.  I
> did find an aritcle on how to set up boot loading on multiple HDD's,
> including cloning /boot/efi but I now can't find it.  Does anyone know of a
> similar article?


Use RAID1 for /boot/efi as well.  The installer should get the details 
right.


> 2) is putting SWAP in a RAID a good idea? Will it help, will it cause
> problems?


It'll be moderately more reliable.  If you have swap on a non-redundant 
disk and the kernel tries to read it, bad things (TM) will happen.

The only "drawback" that I'm aware of is that RAID consistency checks 
become meaningless, because it's common for swap writes to be canceled 
before complete, in which case one disk will have the page written but 
the other won't.  This is by design, and considered the optimal 
operation.  However, consistency checks don't exclude blocks used for 
swap, and they'll typically show mismatched blocks.