[CentOS] CentOS 7 and Areca ARC-1883I SAS controller: JBOD or not to JBOD?

Fri Jan 20 23:34:08 UTC 2017
John R Pierce <pierce at hogranch.com>

On 1/20/2017 9:31 AM, Peter Peltonen wrote:
> I am planning to have RAID1 setup and I am wondering if I should use
> the controller's RAID functionality which has 2GB cache or should I go
> with JBOD + Linux software RAID?
> The disks I am going to use are 6TB Seagate Enterprise ST6000NM0034
> 7200rpm SAS/12Gbit 128 MB
> If hardware RAID is preferred, the controller's cache could be updated
> to 4GB and I wonder how much performance gain this would give me?

if the controller's cache has battery or flash backed writeback 
protection, that should be in play whether you use it as jbod or 
"hardware" raid.   you'll find the biggest performance boost will be on 
OLTP type database operations where many small insert/update 
transactions are being done.... but, those drives are more of a bulk 
storage sort of drive, suitable for things like backup data, media 
servers, rather than database... dedicated database servers generally 
use higher RPM drives or nowdays, enterprise-grade SSD.

john r pierce, recycling bits in santa cruz