The question is about disks that were formatted as 520 or 528 bytes rather than 512 bytes. How does the operating system read data if I cannot access to those disks via hexedit/cat or any viewer?
Is there a way that I can read and write data coming from 520 formatted disks without reformatting the size to 512 on Ubuntu?
If you want to read the data from the disk, you plug it back into the storage device it came out of, along with the rest of the disks that comprised whatever storage array it was a part of.
Linux cannot read disks formatted with 520-byte sectors. (Nor does Windows.) If you want to use this drive with Linux, you need to reformat it to 512-byte sectors. Instructions to do this are very easy to find on the Internet.
Purely for recovery purposes, on linux machines, have a look at the sg_dd, sg_read, sg_read_long utilities from the sg3-utils package. These work on /dev/sg... devices NOT /dev/sd... and should allow to at the very least pull a binary image of the disk, albeit some post processing might be required.
