Re: Software vs. Hardware RAID Data

On Tue, 19 Aug 2008, Mark Wong wrote:

> Hi all,
>
> We started an attempt to slice the data we've been collecting in
> another way, to show the results of software vs. hardware RAID:
>
> http://wiki.postgresql.org/wiki/HP_ProLiant_DL380_G5_Tuning_Guide#Hardware_vs._Software_Raid
>
> The angle we're trying to show here is the processor utilization and
> i/o throughput for a given file system and raid configuration.  I
> wasn't sure about the best way to present it, so this is how it looks
> so far.  Click on the results for a chart of the aggregate processor
> utilization for the test.
>
> Comments, suggestions, criticisms, et al. welcome.

it's really good to show cpu utilization as well as throughput, but how
about showing the cpu utilization as %cpu per MB/s (possibly with a flag
to indicate any entries that look like they may have hit cpu limits)

why did you use 4M stripe size on the software raid? especially on raid 5
this seems like a lot of data to have to touch when making an update.

David Lang