Repairing a corrupt exFat file system

exfatfilesystem-corruptionfilesystems

Long story short : I messed up my GPT and went on to try to fix it without asking anyone, just searching around. Didn't turn out too well.

Right now all I'm concerned about is a 500GB that I formatted as exFat partition with some important files. But on my journey to fix, I may have used the 'fdisk' command on a GParted Live CD I have (couldn't get on any OS) and switched it to ext2. Now I can't get access to it, doesn't show up on Windows or Mac. Only on the partition table as ext2.

I have got access to most of my files through recovery softwares but they cannot recover with the originial directory or file names, which would be a pain to fix.

I want to know if there is a way to change back the file system to exFat without having to format it.

Thanks in advance.

EDIT:

This is how my partitions look like right.
enter image description here

Best Answer

"change back the file system to exFat without having to format it" ... actually, you formated it to ext2. So there is a good chance, that the old "underlying" exFAT is fairly broken, even after a good recovery.

Try and have a look at http://www.cgsecurity.org/wiki/TestDisk

Errors from a bad disk image

Sounds like you're seeing errors in the image cause by a failing drive. I'd use gddrescue instead, it attempts to handle read errors.

Gddrescue's manual is informative, it's section 10 A small tutorial with examples starts with

Example 1: Fully automatic rescue of a whole disc with two ext2 partitions in /dev/sda to /dev/sdb.
Note: you don't need to partition /dev/sdb beforehand, but if the partition table on /dev/sda is damaged, you'll need to recreate it somehow on /dev/sdb.
ddrescue -f -r3 /dev/sda /dev/sdb mapfile
fdisk /dev/sdb
e2fsck -v -f /dev/sdb1
e2fsck -v -f /dev/sdb2

Instead of rescuing directly to a device (/dev/sdb), using a file works. And instead of starting with -r 3 to retry bad sectors 3 times, maybe use the default (0) and -n / --no-scrape to "Skip the scraping phase" to get as much as you can quickly first.

There's also a ddrescueview package that gives a graphic view of a gddrescue map file, that might be interesting:

And monitoring syslog or dmesg should have shown read errors earlier, I'd monitor them while using that drive.

Are there that many important files to backup?

If the files are still readable, and especially if the important files you want to backup are much smaller than the entire drive, just copy those files only and forget about the entire drive image. OS's are easy to reinstall.

Mounting full disk images

Looks like losetup -P creates appropriate partition-loop devices itself, or maybe partprobe or gnome-disk-image-mounter, in addition to kpartx.

Best Answer

Related Solutions

Linux – Why is fsck saying corrupt superblock or partition table and how to fix

Errors from a bad disk image

Are there that many important files to backup?

Mounting full disk images

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