Re: Disk Benchmarking Question

Thanks for the feedback guys. I'm looking forward to the day when we
upgrade to SSDs.

For future reference, the bonnie++ numbers I was referring to are:

Size: 63G

Sequential Output:
------------------------
396505 K/sec
% CPU 21

Sequential Input:
------------------------
401117 K/sec
% CPU 21

Random Seeks:
----------------------
650.7 /sec
% CPU 25

I think a lot of my confusion resulted from expecting sequential reads to
be 4x the speed of a single disk because the disks are in RAID10. I'm
thinking now that the 4x only applies to random reads.

On Sat, Mar 19, 2016 at 6:32 AM, Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com>
wrote:

> On Sat, Mar 19, 2016 at 4:29 AM, Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com>
> wrote:
>
> > Given the size of your bonnie test set and the fact that you're using
> > RAID-10, the cache should make little or no difference. The RAID
> > controller may or may not interleave reads between all four drives.
> > Some do, some don't. It looks to me like yours doesn't. I.e. when
> > reading it's not reading all 4 disks at once, but just 2, 1 from each
> > pair.
>
> Point of clarification. It may be that if two processes are reading
> the data set at once you'd get a sustained individual throughput that
> matches what a single read can get.
>

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*THIS IS A TEST*