PROPER use of the dd command

[mindwave]

Ok, I'm not BRAND new, but i do have a command that ive never used before.

dd,from the cli, makes an exact digital image of a source (floppy, cd etc).

so that it can be restored in the same manner.

NOW.

Lets say i have something on a 10GB hd it has 2 partitions a 2 GB and an 8GB.

there is NOTHING on the 8GB, but it is formatted.

So you run a proper dd command and you end up with a GOOD dd .IMG file.

NOW lets say you want to RESTORE that IMG file to a DIFFERENT 10GB HD.

Would I need to PARTITION the NEW HD in the same way that the OLD one was?

IF the new 10GB hd is already partitioned and formatted, do i need to KILL the partition and format that is there?

OR does the dd command for restoration automatically partition, format and restore everything all at once?

any and all help would be appreciated.

Thanks

J

[devils casper]

hi mindwave !

'dd' command is just like a 'copy' command. difference is in the read/write method and convert options. 'dd' can read from file and write in given Block address and vice versa.
you have to partition the disk manually and dd doesn't care about partitions. it directly deals with byte address.
e.g.

dd if=/dev/myfile of=/dev/hda bs=1200 count=513

copy data from file 'myfile', write in Primary Harddisk 'hda', start writing from byte address 513 and write next 1200 bytes.

this is a very basic example. check manual of 'dd' command. man dd.




Casper

[mindwave]

excellent thanks

i think i'll blow the existing partitions away and repart from scratch

and i tried the man but it didnt seem to exactly address this particular issue