How to extract files from a .dd file?

[Pierre31]

Hello;

I have a file : cpq_cciss-2.6.20-34.rhel4.i686.dd which is designed to build a floppy disk; these floppy is used to hold disk driver which is not on RedHat CD-Rom. But this .dd is not complete: some files, like /drivers/pci.ids are missing.

My idea is to extract all files from .dd file, put missing files and then re-create a new dd file.
But, how can extract all files from initial .dd file, and then recreate a new one?

Thank you for your help.
(sorry for my English)

Pierre S.

[cheesecake42]

Hi Pierre,

You should be able to just mount the .DD file with the mount command and then browse the files/copy them to wherever you want and then add the files you want. Once you have added the files that you want, you should be able to recreate the image with the "dd" command. I haven't actually done this myself but I believe the man pages for those two commands should give you sufficient information on completing the task. If not perhaps someone else will be able to give you a more in depth explanation.

[Pierre31]

Hello Cheesecake42;

It's works and it is very simple! I don't think that a "dd" format can be mounted!
The file system is seen as ext2 and I write on it and the new files are well taking in account. My problem is not completly solved but I can try to continue!
Thank you very much!
Pierre S.

[scathefire]

after you add the files just do

dd if=input/file/name of=/output/file/name

[Pierre31]

Hello scathefire;
I dont understand!
I have issue # mount /dev/fd0 /mnt (thank you Cheesecake42)
then cp pci.ids /mnt
Why can issue a new dd command?
With which /input/file/name and /output/file/name ?
Can you explain please.
Pierre S.

[scathefire]

i suppose in your case the command would look something like:

dd if=/dev/fd0 of=/path/to/some_file_name.dd

this will create a new dd image based upon /dev/fd0. for more information see the man pages for dd

[Pierre31]

// dd if=/dev/fd0 of=/path/to/some_file_name.dd
Yes, of course!

But, I want to acces to files that are inside the /path/to/some_file_name.dd
Not, to .dd raw file.

Pierre S.

[cheesecake42]

I don't think you are going to be able to access the files while it is in .dd form if that is what you are looking for. You will only be able to actually access the files once you have taken the .dd file and then mounted it. So once you have mounted the .dd file, added the files to it, and then created the new .dd file, you will not be able to access the files again until you remount that newly created .dd file.

[Pierre31]

Yes, but I dont need to recreate a .dd file.

Initialy, I want to add a file at driver.dd for example and then rebuild a floppy, not the driver.dd.
Before the post, I have set-up the floppy by the recommanded command
# dd if=driver.dd of=/dev/fd0 bs=1440k
But, I don't know how to add files on the floppy.

So, in response to chesecake42, I do what you suggest
# mount /dev/fd0 /mnt
# ls /mnt
And, here, I see all files that were in driver.dd
then, to add the missing file, I do only:
# cp pci.ids /mnt
# sync
# umount /mnt
If I remount /dev/fd0, I see the new file.

It is what I want.
Thank you
Pierre S.
(ps: the content of the floppy is always wrong, but it is another problem)