Solved Dumb question - linux dd write 0s to multiples disks at once
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@dustinb3403 said in Dumb question - linux dd write 0s to multiples disks at once:
@travisdh1 said in Dumb question - linux dd write 0s to multiples disks at once:
@dustinb3403 said in Dumb question - linux dd write 0s to multiples disks at once:
@scottalanmiller said in Dumb question - linux dd write 0s to multiples disks at once:
With a single command, no. But you can run several commands at once.
That would suffice, what would it look like?
tack a
;to the end of each dd command and put them all on a single lineas
dd if=/dev/zero of=/dev/sdb bs=4k; dd if=/dev/zero of=/dev/sdc bs=4k; dd if=/dev/zero of=/dev/sdd bs=4k; dd if=/dev/zero of=/dev/sde bs=4kright?
That makes one run right after the other, they don't run at the same time.
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@travisdh1 said in Dumb question - linux dd write 0s to multiples disks at once:
dd if=/dev/zero of=/dev/sdb bs=4k
nohup dd if=/dev/zero of=/dev/sdb bs=4k & nohup dd if=/dev/zero of=/dev/sdc bs=4k & nohup dd if=/dev/zero of=/dev/sdd bs=4k &Like that
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@scottalanmiller but nohup from the live us isn't an option.
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@dustinb3403 said in Dumb question - linux dd write 0s to multiples disks at once:
@scottalanmiller but nohup from the live us isn't an option.
Oh, what shell are you in?
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@dustinb3403 said in Dumb question - linux dd write 0s to multiples disks at once:
@scottalanmiller but nohup from the live us isn't an option.
Using Ubuntu live usb?
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Centos 7
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What is the result of this command..
echo $0 -
@scottalanmiller said in Dumb question - linux dd write 0s to multiples disks at once:
What is the result of this command..
echo $0Not at the office, so I don't know
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https://unix.stackexchange.com/revisions/284489/1
dd if=/dev/zero | tee >(dd of=/dev/sdb) >(dd of=/dev/sdc) | dd of=/dev/sdd -
@dustinb3403 said in Dumb question - linux dd write 0s to multiples disks at once:
Is it possible to use linux DD to write 0's to multiple disks at once?
The goal would be to wipe 4 drives at once.
What if you create a SW RAID 10 with them quick, then write zeros?
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Does writing zeros to an SSD drive affect the drive life?
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No need to wipe all the disks. It's a waste of time.
- If you wanted to erase the partition table you don't have to erase the whole disk. Just the first / last bytes of the drive. Or just remove it with fdisk or parted.
- If you wanted to remove superblocks after an earlier md raid installation you wouldn't need to wipe the disk either. You do:
mdadm --zero-superblock /dev/sdX
You could also use
wipefs -a /dev/sdXto remove just partition tables and raid signatures - if you have it installed.And as soon as you put together a raid-10 it will start synchronizing the disk and write the same zeros one more time.
If you really, really wanted to wipe the drive so no residual data where on them, wipe just what is needed to make a raid-10 array out of it. Then wipe the array with zeros, as a block device. It will save a lot of time. As the synchronization process will write the zeros for you on the other drives.
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@obsolesce said in Dumb question - linux dd write 0s to multiples disks at once:
@dustinb3403 said in Dumb question - linux dd write 0s to multiples disks at once:
Is it possible to use linux DD to write 0's to multiple disks at once?
The goal would be to wipe 4 drives at once.
What if you create a SW RAID 10 with them quick, then write zeros?
That would be faster. Or RAID 1. Any RAID, actually.
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@aaronstuder said in Dumb question - linux dd write 0s to multiples disks at once:
Does writing zeros to an SSD drive affect the drive life?
No, shouldn't affect anything unless you are trying to obfuscate the old data
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"screen" is available within the bootable USB.
screen dd if=/dev/zero of=/dev/sda1 bs=1M
Ctrl-A then D to detach
Up arrow then enter 3 more times...This will continue to run even if the console is lost (ssh) or if the user logs out
screen -Rto re-attach a session if you want to check the statusHaving said that:
dd if=/dev/zero of=/dev/sda bs=512 count=1 conv=notrunc
Should take only seconds and delete the partition table and is less work than using fdisk in the event that wipefs isn't available on the bootable USB. -
@scottalanmiller said in Dumb question - linux dd write 0s to multiples disks at once:
@travisdh1 said in Dumb question - linux dd write 0s to multiples disks at once:
dd if=/dev/zero of=/dev/sdb bs=4k
nohup dd if=/dev/zero of=/dev/sdb bs=4k & nohup dd if=/dev/zero of=/dev/sdc bs=4k & nohup dd if=/dev/zero of=/dev/sdd bs=4k &Like that
Dang it, I'm always mixing those up.
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@scottalanmiller said in Dumb question - linux dd write 0s to multiples disks at once:
@travisdh1 said in Dumb question - linux dd write 0s to multiples disks at once:
dd if=/dev/zero of=/dev/sdb bs=4k
nohup dd if=/dev/zero of=/dev/sdb bs=4k & nohup dd if=/dev/zero of=/dev/sdc bs=4k & nohup dd if=/dev/zero of=/dev/sdd bs=4k &Like that
And if you're set on a one-liner like before:
for i in {b..d}; do nohup dd if=/dev/zero of=/dev/sd$i bs=4k &; done -
Another way would be to use
make. Just create a makefile with:all: disk1 disk2 disk3 .PHONY: disk1 disk1: dd if=/dev/zero of=/dev/sdb bs=4k .PHONY: disk2 disk2: dd if=/dev/zero of=dev/sdc bs=4k .PHONY: disk3 disk3: dd if=/dev/zero of=/dev/sdd bs=4kThen just run
make -jand it will run all of the targets in parallel. If you want them to loop then just don't give the-jflag. -
@stacksofplates : Now you're just showing off
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@manxam said in Dumb question - linux dd write 0s to multiples disks at once:
@stacksofplates : Now you're just showing off
Ha I didn't mean for it to look like that, but you did make me realize I made a mistake so I'll have to fix it. Make has a lot of uses outside of jsut building software. It's a pretty awesome utility.
