On Wed, Feb 2, 2011 at 7:00 PM, Craig Ringer
<craig@postnewspapers.com.au> wrote:
> Whatever RAID controller you get, make sure you have a battery backup
> unit (BBU) installed so you can safely enable write-back caching.
> Without that, you might as well use software RAID - it'll generally be
> faster (and cheaper) than HW RAID w/o a BBU.
Recently we had to pull our RAID controllers and go to plain SAS
cards. While random access dropped a bit, sequential throughput
skyrocketed, saturating the 4 lane cable we use. 4x300Gb/s =
1200Gb/s or right around 1G of data a second off the array. VERY
impressive.