On Wed, Sep 9, 2015 at 4:25 PM, Carlos E. R. <robin.listas@telefonica.net> wrote:
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On 2015-09-09 21:07, Greg Freemyer wrote:
Not responding directly to your question, but you know I make a lot of "dd-equivalent" disk images.
I prefer to create EWF formatted images. They have embedded CRC checksums as well as an overall hash. You can verify their integrity without having to have an external hash file to compare against.
Ah, that's interesting. I don't know if I need that much, though. I'll explain my purpose.
I have a double boot laptop, windows 7 / Linux. Microsoft proposes that I update to Windows 10. Before doing that, I want to create an image backup that allows me to restore Linux, if destroyed, or W7, if I want to go back to it.
Thus I want the image for a limited time only: I either continue using W10, or restore W7.
I have found hardware issues can corrupt the original image more often than you would think. I made about 65 images in one week last summer, then I made copies of all of them. I used numerous customer provided PCs to do the work. I used ewfverify on all of them to make sure they were good. I don't recall exactly, but there were 4 or 5 I had to re-perform because the verify failed. Also, I ended up tossing one of my destination drives because the images it held were all flaky. But yes, even with random PCs 95% of the time it works as planned. And if you are using a trusted PC then the odds are much higher. PCs that corrupt images tend to have bad RAM or bad cables, but it can be any flaky item in the PC to cause a verify failure.
ewfacquire is in the distro and will create EWF formatted images. It will also split them up into 2GB segment files (by default). image.E01, image.E02, ....
You can use ewfverify to check the CRCs and hash verify the image as valid.
If not, does it store recovery data to repair it?
man ewfrecover I don't recall ever using it. I keep at least 2 copies of all images. If one of them fails to verify, I make another copy of the good one.
When you want to access it as a linear dd image equivalent you use ewfmount.
The only confusing part (for me) is if you want to do a partition mount, you have to do 2 mounts:
ewfmount first exposes the EWF image as a single large virtual disk
Then a nomal loop mount is needed to mount a specific partition.
I can try, I guess...
I'm installing now libewf2 and libewf2-tools to try.
As I said, this is going a little above and beyond, but they are my everyday tools. I need trustworthy images that I can depend on years later. Greg -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org