On Wed, Apr 2, 2008 at 10:44 AM, Justin Piszcz <jpiszcz@xxxxxxxxxxxxxxx> wrote:
>
>
>
> On Wed, 2 Apr 2008, Conway S. Smith wrote:
>
>
> > On Wed, 2 Apr 2008 08:16:16 -0400 (EDT)
> > Justin Piszcz <jpiszcz@xxxxxxxxxxxxxxx> wrote:
> >
> > >
> > >
> > > On Tue, 1 Apr 2008, Beolach wrote:
> > >
> > >
> > <snip>
> >
> > >
> > > >
> > > > Also, would you be willing to share your script for averaging 3
> > > > bonnie++ runs? I'm too lazy to write my own, so I've just been
> > > > doing single runs.
> > > >
> > >
> > > I do not have a single script to do it actually, it works like this:
> > >
> > > # Run bonnie 3 times (script).
> > > for i in 1 2 3
> > > do
> > > /usr/bin/time /usr/sbin/bonnie++ -d /x/test -s 16384 -m p34 -n
> > > 16:100000:16:64 > $HOME/test"$i".txt 2>&1 done
> > >
> > > # then get the results
> > > $ cat test* | grep ,
> > >
> p34,16G,80170,99,261521,43,109222,14,82516,99,527121,39,864.3,1,16:100000:16/6411428,83,+++++,+++,6603,30,7780,56,+++++,+++,8959,45
> > >
> p34,16G,79428,99,266452,44,111190,14,82087,99,535667,39,884.3,1,16:100000:16/643388,26,+++++,+++,7185,34,6364,46,+++++,+++,4040,22
> > >
> p34,16G,78346,99,255350,42,111591,14,82153,99,527210,38,850.4,1,16:100000:16/642916,21,+++++,+++,18495,81,5614,41,+++++,+++,15727,83
> > >
> > > $ cat test* | grep , > results
> > >
> > > $ avgbonnie results
> > >
> p34,16G,79314.7,99,261108,43,110668,14,82252,99,529999,38.6667,866.333,1,16:100000:16/64,5910.67,43.3333,0,0,10761,48.3333,6586,47.6667,0,0,9575.33,50
> > >
> > > Nothing special for the average, just a long awk statement
> > > hardcoded for 3 runs:
> > >
> > > grep ',' "$1" | awk -F',' '{print $1, $2, c += $3/3, d += $4/3, e
> > > += $5/3, f += $6/3, g += $7/3, h += $8/3, i += $9/3, j += $10/3, k
> > > += $11/3, l += $12/3, m += $13/3, n += $14/3, $15, p += $16/3, q +=
> > > $17/3, r += $18/3, s += $19/3, t += $20/3, u += $21/3, v += $22/3,
> > > w += $23/3, x += $24/3, y += $25/3, z += $26/3, aa += $27/3}' |
> > > tail -n 1 | sed 's/\ /,/g'
> > >
> > > $ grep ',' results | awk -F',' '{print $1, $2, c += $3/3, d +=
> > > $4/3, e += $5/3, f += $6/3, g += $7/3, h += $8/3, i += $9/3, j +=
> > > $10/3, k += $11/3, l += $12/3, m += $13/3, n += $14/3, $15, p +=
> > > $16/3, q += $17/3, r += $18/3, s += $19/3, t += $20/3, u += $21/3,
> > > v += $22/3, w += $23/3, x += $24/3, y += $25/3, z += $26/3, aa +=
> > > $27/3}' | tail -n 1 | sed 's/\ /,/g'
> > >
> p34,16G,79314.7,99,261108,43,110668,14,82252,99,529999,38.6667,866.333,1,16:100000:16/64,5910.67,43.3333,0,0,10761,48.3333,6586,47.6667,0,0,9575.33,50
> > >
> > > Hope this helps..
> > >
> > >
> >
> > Thanks! Although now I'll have to get around to learning awk so I can
> > understand that. ;-)
> >
> >
> > >
> > > >
> > > > [1] My bonnie++ results:
> > > > <http://www.xmission.com/~beolach/bonnie++_4disk-ls.html>
> > > >
> > > Intriguing results you have there, nice sequential read speed.
> > > What FS are you using?
> > > Any special options?
> > >
> >
> > XFS, no special mkfs options, noatime,nodiratime mount options.
> >
> >
> > > What read-ahead are you using?
> > > What is your stripe_cache_size?
> > > These heavily affect performance.
> > >
> > >
> >
> > I haven't tried tweaking these yet. Are they likely to change which
> > chunksize performs best? I was thinking I'd figure out a chunksize,
> > and then look at other performance tweaks. But I'm worried that I
> > might later find out a different chunksize would have been better,
> > and chunksize is much harder to change than read-ahead.
> >
> > $ blockdev --getra /dev/md1
> > 3072
> > $ cat /sys/block/md1/md/stripe_cache_size
> > 256
> >
> The stripe_cache_size will make a huge difference with RAID5, try up to
> 32768.
That's 512MB for a 4-disk array. Hopefully the get_priority_stripe
patch alleviates the pressure to push stripe_cache_size this high.
--
Dan
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