[CentOS] CentOS 6.0 and 3ware 9650SE series RAID Performance

Thu Sep 1 23:47:42 UTC 2011
Craig White <craig.white at ttiltd.com>

I'm surprised that you can actually turn it on without a battery. I suspect that this is not a write-through/write-back cache but be forewarned that if there's no battery, it's possible that things you thought were written to the hard drive on shutdown/restart/hang/crash might not ever be written to the hard drive(s)

Craig

On Sep 1, 2011, at 4:17 PM, Austin Godber wrote:

> Hi Craig,
> 
> Thanks for the suggestion.  I would if I could.  I'd also probably try another file system.  Though the good news is, enabling the write cache on that array has improved things significantly.  Which, in my case, was:
> 
> tw_cli /c2/u0 set cache=on
> 
> Now, if only I had the battery backup unit for the card.
> 
> Thanks, everyone for their suggestions.  For now I am happy with the situation, but I'd be interested to hear the experiences of others.
> 
> Austin
> 
> On Thu, Sep 1, 2011 at 3:58 PM, Craig White <craig.white at ttiltd.com> wrote:
> 
> On Sep 1, 2011, at 1:41 PM, Austin Godber wrote:
> 
> > Hello,
> >
> > Does anyone have experience using a 3ware 9650SE series raid controller on CentOS 6.0?
> ----
> use RAID 10
> 
> Unless something has changed, RAID 5 is notoriously slow on the 3Ware controllers. Whatever you do will only incrementally speed things up. If performance is desired, RAID 5 is not the way to go.