Re: Best suiting OS

[Karl Denninger <karl@xxxxxxxxxxxxx>]

Scott Carey wrote:

On 10/5/09 11:15 AM, "Karl Denninger" <karl@xxxxxxxxxxxxx> wrote:

  

I'm running the 9650s in most of my "busier" machines.  Haven't tried a
PERC card yet - its on my list.  Most of my stuff is configured as RAID
1 although I have a couple of RAID 10 arrays in service; depending on
the data set and how it splits up I prefer to have more control of how
I/O is partitioned rather than let the controller pick through striping.

I don't think I have any of the 95xx stuff out in the wild at present;
it didn't do particularly well in my testing in terms of performance.

-- Karl
    

Let me make sure I clarify here --

The 3ware 9[56]xx issues I have seen were with throughput on larger RAID
array sizes -- 8+ disks total.  On smaller arrays, I have not tested.

  

Interesting... I'm curious if that's why I haven't run into it - I get damn close to N x rotational on sequential I/O out of these boards; you can't really do better than the physics allow :)

I'll have to play with some larger (> 8 unit) Raid 1 and Raid 10 arrays and compare to see if there's a "knee" point and whether its a function of the aggregation through the chipset or whether it's a card issue.  I suspect it's related to the aggregation as otherwise I'd have seen it on some of my larger configurations, but I tend to run multiple adapters for anything more than 8 spindles, which precludes the situation you've seen.

Of course if you NEED 12 spindles in one logical device for capacity reasons........

-- Karl

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