You dont mention what software you are using. i am familiar with how X-Ways does reverse imaging, so ill speak to that a bit.
i believe reading backwards, at least with X-Ways, disables CRC checks and whatnot when reading sectors
from the X-Ways manual:
Quote::
In conjunction with simultaneous I/O you may also have WinHex copy the sectors of a disk in reverse direction, backwards from the end of the source disk. Useful if the source disk has severe physical defects that for example cause a disk imaging program or your entire computer to freeze or crash when reaching a certain sector. In such a case you can additionally create an image in reverse order, by reading sectors from the disk backwards one by one, or better, you can even automatically complete an existing incomplete unsegmented conventional ("forward") raw image from the rear end to get an image that is as complete as possible, filled from both ends, with ideally only a small zeroed gap in the middle that represents the unreadable damaged spot on the source hard disk. For that you simply select an incomplete raw image file that you already have as a destination file, and you will be asked whether you wish to complete it instead of overwrite. WinHex will do the rest, e.g. allocate the missing sectors in the image file (zeroed out) so that it has the complete size of the source disk and then fill the file backwards as much as possible. Be sure to create reverse images on NTFS volumes, not FAT32. The source start sector to specify for reverse imaging is the same as for conventional forward images, i.e. usually 0 when imaging a complete hard disk.
so in general thats the idea with reverse imaging.
i know X-ways does some different things when it comes to imaging disks in general and it is one of, if not the only, tool out there that does reverse imaging automatically
↧