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maggie

Member

Registered: 2011-02-12

Posts: 255

Can the dd command run on 3 HDDs at the same time [solved]

To prepare 3 HDDs for a raid and dmcrypt, the wiki shows to wipe with random data first. Can I do this on all 3 drives at the same time just with three terminals running the same command in parallel?

cryptsetup open --type plain /dev/sdb1 partb --key-file /dev/random
cryptsetup open --type plain /dev/sdc1 partc --key-file /dev/random
cryptsetup open --type plain /dev/sdd1 partd --key-file /dev/random

Then in three different terminals

dd if=/dev/zero of=/dev/mapper/partb status=progress
dd if=/dev/zero of=/dev/mapper/partc status=progress
dd if=/dev/zero of=/dev/mapper/partd status=progress

The chip is a quad so it shouldn't be cpu limiting but will I saturate the SATA bus?

edited on Dec 3rd - I was able to run these in parallel and all three took about 10 h to finish and finished within 14 minutes of each other.

Last edited by maggie (2015-12-03 20:32:12)

frostschutz

Member

Registered: 2013-11-15

Posts: 1,499

Re: Can the dd command run on 3 HDDs at the same time [solved]

normally this should work fine

I also like `shred -v -n 1`... it writes (pseudo) random data as fast as dd writes zeroes and it shows progress as well (which dd didn't used to do, but status=progress is quite nice).

Last edited by frostschutz (2015-12-03 00:34:50)