Thread: Software vs. Hardware RAID Data

Software vs. Hardware RAID Data

From
"Mark Wong"
Date:
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.

Regards,
Mark

Re: Software vs. Hardware RAID Data

From
david@lang.hm
Date:
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

Re: Software vs. Hardware RAID Data

From
Tommy Gildseth
Date:
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
>
> Comments, suggestions, criticisms, et al. welcome.


The link to the graph for "Two Disk Software RAID-0 (64KB stripe)"
points to the wrong graph, hraid vs sraid.


--
Tommy Gildseth

Re: Software vs. Hardware RAID Data

From
"Mark Wong"
Date:
On Tue, Aug 19, 2008 at 10:49 PM,  <david@lang.hm> wrote:
> 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)

Ok, we'll add that and see how it looks.

> 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.

I'm sort of taking a shotgun approach, but ultimately we hope to show
whether there is significant impact of the stripe width relative to
the database blocksize.

Regards,
Mark

Re: Software vs. Hardware RAID Data

From
"Mark Wong"
Date:
On Wed, Aug 20, 2008 at 12:53 AM, Tommy Gildseth
<tommy.gildseth@usit.uio.no> wrote:
> 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
>>
>> Comments, suggestions, criticisms, et al. welcome.
>
>
> The link to the graph for "Two Disk Software RAID-0 (64KB stripe)" points to
> the wrong graph, hraid vs sraid.

Thanks, I think I have it right this time.

Regards,
Mark