[CentOS] Centos 7 RAID tutorial?

Mon Sep 8 03:01:10 UTC 2014
Keith Keller <kkeller at wombat.san-francisco.ca.us>

On 2014-09-08, Valeri Galtsev <galtsev at kicp.uchicago.edu> wrote:
> Even more: system failure or power loss is more likely to destroy all data
> on software RAID than on a single drive when there is a lot of IO present
> (to the best of my understanding, loss of cache software RAID is using is
> more catastrophic compared to journaled filesystem under same
> circumstances - somebody may correct me). So, there may be worth thinking
> about hardware RAID.

I think an essential feature of any md RAID that's not a RAID1 is a UPS
and a mechanism for a clean shutdown in case of extended power failure.
(An md RAID1 might be okay in this instance, but I wouldn't want to risk
it.)  But this is true for any RAID, which is why many controllers come
with a BBU (and if you don't have a BBU on your hardware RAID controller,
then you absolutely need the UPS setup I described).

OTOH, the OP wasn't clear on what he was doing; perhaps he is just
playing around, and doesn't care about data preservation at this time.
If you're just testing performance then data integrity in the face of a
power failure is less of a concern.



kkeller at wombat.san-francisco.ca.us