[CentOS] Help finishing off Centos 7 RAID install

[Keith Keller]

On 2019-01-09, Gordon Messmer <gordon.messmer at gmail.com> wrote:
> On 1/9/19 2:30 AM, Gary Stainburn wrote:
>
>> 2) is putting SWAP in a RAID a good idea? Will it help, will it cause
>> problems?
>
> 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.

If the swap is RAID1 on its own partitions (e.g., sda5/sdb5), then
CHECK_DEVS in /etc/sysconfig/raid-check can be configured to check
only specific devices.

--keith

-- 
kkeller at wombat.san-francisco.ca.us