[CentOS] Poor RAID performance new Xeon server?

Sun Jan 11 18:49:29 UTC 2009
Les Mikesell <lesmikesell at gmail.com>

Stewart Williams wrote:
>
> I am no expert on RAID, so you have opened my eyes to somethings I 
> wasn't aware of.
> 
> I am considering disabling the onboard RAID in the BIOS and 
> re-installing CentOS and configuring the 4 drives as RAID 10 just to see 
> what the performance is like.

Yes, unless you have an expensive hardware raid with its own cpu and 
buffers on board, software raid 1 or 10 is better.  I like to stick to 
raid1 where practical size-wise so that you can recover data from any 
single disk and you can keep seeks on different filesystems from 
competing with each other.

> Or I may purchase a card as you advise. Would I benefit from buying a 
> SCSI/or SAS card and drives for my requirements? Basically the main role 
> of the machine is to serve a ~600MB file via samba to 5 Windows XP cient 
> PC's on a gigabit network.

After the 1st read, that should live entirely in RAM cache and the speed 
you can serve it won't be limited to the underlying disk except for 
writes that eventually have to flush back.  At least until you consume 
the RAM doing something else.

-- 
   Les Mikesell
    lesmikesell at gmail.com