While I was switching distros, I accidentally broke a partition. I’m almost certain that all the data is there, but it doesn’t have a filesystem (I used ext4). Is there anything I can do to fix it, similar to changing the file extension without changing the contents. PS: It’s a data partition. I was trying to resize it, accidentally also moved it to the left, found out that it was taking forever to move it, so I cancelled it. Finished the move to the left operation (I think), but it threw up an error about the filesystem. I don’t remember what it was, though.
Thanks to everyone who suggested Testdisk. It worked almost perfectly.
You can try
fdisk.If the partition table is there - create a new partition at the exact same location, of the exact same size.
If the partition table is not there - create *the exact same type (mbr vs gpt) partition table, then do the first if.
Fdisk should tell you that it found a filesystem signature. Do not wipe it.
… exact same starting block, size and geometry.