hi!
can anyone mail me tgz of bonnie or the web site from where it is available?
Thanks & Regards,
Abhishek
> -----Original Message-----
> From: Corin Hartland-Swann [SMTP:[EMAIL PROTECTED]]
> Sent: Thursday, July 27, 2000 7:53 AM
> To: Gregory Leblanc
> Cc: Holger Kiehl; [EMAIL PROTECTED]
> Subject: RE: Question on disk benchmark and fragmentation
>
>
> Gregory,
>
> On Thu, 27 Jul 2000, Gregory Leblanc wrote:
> > > 6) Use tiotest, NOT bonnie! Try multiple threads (I use 1, 2,
> > > 4, 8, 16,
> > > 32, 64, 128, 256 threads - this is perhaps excessive!)
> >
> > What size datasets are you using?
>
> I use 1G if I'm feeling like making absolutely sure it's fair, or else
> something like 256M if I'm trying to get it done quickly.
>
> > Bonnie++ is still a good benchmark, although it stresses things
> > differently.
>
> I haven't used bonnie++ actually...
>
> > The maximum number of threads that you should need to
> > (or probably even want to) run is between 2x and 3x the number of
> > disks that you have installed. That should ensure that every drive is
> > pulling 1 piece of data, and that there is another thread that is
> > waiting for data while that one is being retrieved.
>
> I believe in seeing how the performance breaks down under extreme
> stress. With a threaded database like mysql (one of the primary uses for
> our RAID arrays) you could quite easily have numerous threads all trying
> to read and write from the array simultaneously.
>
> When I was comparing performance of RAID0+1 to RAID5 there was a big
> difference in how quickly (as per number of threads) they ground to a
> halt. Here's an example:
>
> ./tiobench.pl --size 256 --dir /mnt/md3/ --block 4096 --threads 1
> --threads 2 --threads 4 --threads 16 --threads 32 --threads 64
> --threads 128 --threads 256
>
> Linux Kernel 2.2.14, RAID 0+1
>
> Dir Size BlkSz Thr# Read (CPU%) Write (CPU%) Seeks (CPU%)
> ----- ------ ------- ---- ------------- -------------- --------------
> /mnt/ 256 4096 1 46.3288 25.6% 40.3105 47.2% 165.171 0.66%
> /mnt/ 256 4096 2 35.3465 21.9% 39.5187 45.9% 193.171 0.67%
> /mnt/ 256 4096 4 29.1810 18.0% 38.7580 45.0% 214.686 0.89%
> /mnt/ 256 4096 16 26.9373 17.3% 36.5620 42.2% 220.682 0.93%
> /mnt/ 256 4096 32 21.4527 24.1% 34.7506 40.0% 216.958 0.97%
> /mnt/ 256 4096 64 12.7891 47.4% 31.7158 36.1% 202.744 1.05%
> /mnt/ 256 4096 128 8.65209 80.6% 27.8459 31.2% 200.230 3.27%
> /mnt/ 256 4096 256 5.41081 131.% 24.6386 27.3% 193.811 16.1%
>
> Linux Kernel 2.2.14 with Mika's read-balance patch, RAID 0+1
>
> Dir Size BlkSz Thr# Read (CPU%) Write (CPU%) Seeks (CPU%)
> ----- ------ ------- ---- ------------- -------------- --------------
> /mnt/ 256 4096 1 46.6853 24.6% 38.2826 44.2% 176.209 0.39%
> /mnt/ 256 4096 2 59.6558 40.3% 38.7603 43.6% 221.300 0.69%
> /mnt/ 256 4096 4 60.6616 43.6% 38.2311 42.9% 263.113 0.89%
> /mnt/ 256 4096 16 51.5140 37.6% 37.1443 42.1% 302.154 1.05%
> /mnt/ 256 4096 32 47.0307 34.9% 35.1884 40.1% 329.017 1.33%
> /mnt/ 256 4096 64 42.1452 33.2% 33.0139 37.3% 341.591 1.41%
> /mnt/ 256 4096 128 27.4339 36.0% 30.8700 34.3% 332.434 1.53%
> /mnt/ 256 4096 256 15.5834 76.4% 28.2604 31.1% 321.990 13.2%
>
> Linux Kernel 2.2.14 with Mika's read-balance patch, RAID 5
>
> Dir Size BlkSz Thr# Read (CPU%) Write (CPU%) Seeks (CPU%)
> ----- ------ ------- ---- ------------- -------------- --------------
> /mnt/ 256 4096 1 67.5911 38.8% 24.3309 34.9% 167.331 0.41%
> /mnt/ 256 4096 2 60.4156 49.0% 24.5966 37.1% 208.991 0.67%
> /mnt/ 256 4096 4 46.5667 38.1% 24.4007 37.2% 247.676 0.90%
> /mnt/ 256 4096 16 27.7189 32.6% 24.3155 37.5% 282.041 1.12%
> /mnt/ 256 4096 32 14.4717 45.2% 23.9831 36.8% 301.291 1.32%
> /mnt/ 256 4096 64 8.39616 82.4% 22.5777 34.1% 299.902 1.67%
> /mnt/ 256 4096 128 6.77856 103.% 20.8036 30.6% 276.423 16.7%
> /mnt/ 256 4096 256 6.14939 115.% 19.0964 27.6% 266.183 35.5%
>
> This shows the quite interesting result that (for reads) RAID-5 starts
> off with 1 thread out-performing RAID-0+1 (68 vs 47), drops to the same
> level with 2 threads (60 vs 60), and rapidly decreases thereafter, eg
> at 64 threads it's 8 vs 42.
>
> Of course, because of that slight hiccup, RAID-0+1 arrays will fail
> (recoverably, but still bring the machine down) with one faulty
> disk. So we had to go with RAID-5 anyway...
>
> > Heh, I'm using it because it provides redundancy, the added speed from
> > Mika's RAID 1 read balancing patch is just a perk... HTH,
>
> Yeah, maybe I was being slightly unrealistic. But the performance is
> still mighty nice...
>
> Regards,
>
> Corin
>
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