How to read/mount a .gz.dd image file?

Question

I have a partition file (a .gz.dd file) that I need to read the files from. I'm new to Linux and I don't know how I can read/mount .dd files in Ubuntu. Would you guys tell me the procedure of reading the file? Thanks.

Solution 1

Are you sure it's not a .dd.gz file?

Here's how you uncompress a gzipped file:

gunzip example.dd.gz

This should create a file named example.dd in your current working directory.

To mount a dd image file, create a directory, and mount the image to that directory:

$ mkdir exampledir/
$ mount -o loop example.dd exampledir/

You may need to specify more options to the mount command depending on what type of image your file is.

You can now view the files inside the image by browsing exampledir/.

Solution 2

If you want to read the files on-the-fly from your (gzip) compressed filesystem without having to unpack it, use mksquasfs and dd to create it in the first place.

You can also choose the compression with the -comp option of mksquashfs, e.g. gzip, lzo, xz etc.

See this answer on how to do it (backup/create image, mount one partition of a whole diskimage with the help of kpartx, etc.).

Comments

[nanofarad]

Is it gz.dd, or dd.gz? I'd expect the latter to be more common.

[Wise]

It was a .gz.dd file. But I renamed it to a dd.gz file and did the procedure you explained and it worked perfectly. Thanks for your help!

[Cadoiz]

Linux isn't so much about the file extensions, the .dd is merely for better readability. Meanwhile .gz is more seriously used for compressed files, so the file would more canonically be named example.dd.gz

[Cadoiz]

You can also consider this answer.