I am a little fuzzy on RAID. What is the fastest RAID-0 (striping) array arrangement for what I have? I have eight 68-pin 9.1GB SCSI 10,000 RPM drives, total 72GB (approx.) I already have an 80GB backup drive so I am not looking for data loss risk. I am trying to get the max speed out of all these drives (striping). I think a single channel u160 can max out the RAID striping on all eight, but I'm not sure -- not sure if the u130 can either. If not, what are the most drives I can stripe before performance stops increasing? What will be overkill? How do I max out these eight drives with striping?
The challenge in building your own SAN is end-to-end engineering. The PC with highest CPU number isn't necessarily the fastest for your application. You have to consider all the factors.
In general, I would say for eight high-performance drives you would benefit more than one controller unless you have a custom controller. But without knowing the specifics of the hardware and your block sizes, read/write mix, etc., we couldn't get to the best answer.
However, while you've probably already done this, I would like to point out that matching your block size to your application -- which most people never do -- has a much larger impact on end-to-end performance than what we're doing here.
The kinds of numbers we would get -- the specs we would create -- by doing this low-level engineering are the numbers the vendors use to sell SANs and NAS devices. As the independant reviews point out time after time, these numbers have little relationship to the performance end users actually experience.
This was first published in March 2003