Обсуждение: Software vs. Hardware RAID Data
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
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
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
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
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