# Can dd be used on a live system?



## jemate18 (Feb 15, 2009)

I have an FreebSD 7.1 ftp server setup... I access it via ssh on my laptop in our office.

If i'm in that system through ssh, can i use dd to back the full HD including the partition tables and all? 

dd if=/dev/ad0s1 of=/usr/home/yyy/backup 

then how do i get that backup to be stored in my laptop? Do i have to log off via ssh and use scp for it? 

Other thing.... if i execute dd with someone transacting/downloading with FTP on that server.. Will dd fail?

Thanks


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## Pushrod (Feb 16, 2009)

I don't see dd failing. What I do see is it potentially copying data that is not in a consistent state, making the copy partially corrupt. If you mount it read-only while you dd, you should be fine.


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## graudeejs (Feb 16, 2009)

if you use UFS2, man dump, man restore
they cover how to back up over internet
or
http://forums.freebsd.org/showthread.php?t=185
fallow this, and when finished simply use scp to copy over net


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## vermaden (Feb 16, 2009)

killasmurf86 said:
			
		

> and when finished simply use scp to copy over net


You can use pipe to sent it directly without using local space:
[cmd=]% dump -0 -f - /home | ssh backup@server.org -c blowfish "gzip -c -9 | dd > /storage/backup/home.dump.gz"[/cmd]


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