dd oflag=direct performance

[Michael J. Baars]

Hi,

I needed to zero out my hard drive because one of my nodes has become unstable. 
To this purpose I used coreutils dd with the following command line arguments

dd if=/dev/zero of=/dev/mmc... status=progress

and I noticed how slow this program is in doing the job. So I tried a couple of 
different settings, like

bs=1048576 oflag=direct

but without significant improvement. The results are always the same... around 
25 mb/s.

Then I remembered this little benchmark I write not so long ago, please do have 
a look at it, it won't destroy your drive.

I included the results obtained by running the benchmark on the computer I'm 
currently working on, so you can compare them to your own.

Hope that one of you feels inspired enough you to pick up the dd source codes 
and finish the job.

Best regards,
Mischa Baars.

benchmark_coreutils.tar.xz
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