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rothloup avatar Ubuntu

ext4 FS image gets corrupted on first mount

cn flag
rothloup

I"m in the process of replacing my M.2 SSD with a new and larger one. I want to save an image of my existing partitions before I take out my old SSD so that I can refer to it when setting up my new install and make sure I don't lose anything. I only have one SSD slot in my machine so I can't use the SSD itself, so that's what the image files are for.

I thought this would be fairly straightforward, but I'm running into a weird problem. The image creation appears to execute without a problem and I can loop-mount the image without a problem. But after poking around the mounted filesystem for a bit, I get all sorts of errors, such as

"ls:  reading directory <directory> : Bad message"

I created the images with a simple dd command:

dd if=/dev/nvme0n1p5 of=backup.img bs=64kb status=progress

When they were finished being created, I checked the images without mounting them:

fsck.ext4 backup.img

which then reported that the image was clean.

I then mount the image:

mount backup.img <mnt_pnt>

I then do an 'ls -R' command, and I get the "bad message" error mentioned above.

If I then unmount the filesystem and run fsck again, it reports all sorts inode errors.

If I mount the actual partition directly, there are no errors and the files that were listed with the "Bad message" error have no error.

Base system is a Kubuntu 20.04. I made sure to force an fsck on all partitions before beginning the backup. Backups are being placed on a NAS drive mounted via CIFS.

Procedure above is being performed on a Kubuntu 21.20 Live USB system.

What am I doing wrong?

EDIT: I've looked at CloneZilla and fsarchiver. They seem to promise a lot, but my issue is that I don't want to -restore- these filesystems after I've imaged them. I just want to be able to MOUNT them on a new, fresh ubuntu install and extract and files I need. I tried CloneZilla's instructions for doing so (which they themselves state is a work-around hack) and it couldn't mount the image after I decompressed it. fsarchiver I'm not sure about yet.

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dd
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rothloup avatar Ubuntu
cn flag
rothloup

In case anyone else runs into this: I ended up using e2image to image the partitions instead of dd directly. It appeared to make the images without any of the issues I listed in my question, and I could mount the images as a loopback device.

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br flag
Azendale
I might also mention that using rsync with the `-ax --numeric-ids` flags is a great tool: you can restore an entire Linux based OS using it, only having to update the `/etc/fstab` with new FS UUIDs and installing a bootloader (grub with chroot method). That saves a TON of space compared to disk images.
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