dd as an imaging solution.

[Sean Bryant]

Dominic Marks wrote:
> On Sat, 03 Feb 2007 19:43:42 -0500
> Sean Bryant <sbryant at elgia.com> wrote:
> 
>> Several months ago I was using Freesbie 1.x to dd a harddrive across the 
>> network as a drive duplication effort. This worked 7 computers got the 
>> image. I'm trying to do this again so I got the new Freesbie release 2.0 
>> and fired it up across the computers and tried something simple such as:
>>
>> dd if=/dev/ad0 bs=1m | nc othercomputer 10000 on the image provider
>>
>> nc -l 10000 | dd of=/dev/ad0 bs=1m on the computer to receive the image.
>>
>> I received an operation not permitted. My first thought was they must be 
>> mounted. a quick check, and it seems they weren't.
>> Next, am I really root? And sure enough I was. After a bit of discussion 
>> in #freesbie on freenode got me to set kern.geom.debugflags to 16 and I 
>> was able to write to ad0 like I had previously done. Yet when I tried to 
>> write to an individual slice I was presented with the same error.
>>
>> Anyone have any clue ? The eventual goal is to have a mass imaging all 
>> at once with dd, nc and tee
> 
> Check out G4U (NetBSD based)
> 
>> _______________________________________________
>> freebsd-stable at freebsd.org mailing list
>> http://lists.freebsd.org/mailman/listinfo/freebsd-stable
>> To unsubscribe, send any mail to "freebsd-stable-unsubscribe at freebsd.org"
> 
> Dominic
> _______________________________________________
> freebsd-stable at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-stable
> To unsubscribe, send any mail to "freebsd-stable-unsubscribe at freebsd.org"

The only problem I can see here is that multiple parallel reads will 
have serious performance impacts, thus greatly increasing the cloning of 
the disk.

The solution with dd, tee and netcat would just daisy chain the copy 
across the network which would be way faster.