[PLUG] Imaging CF card...

[Rodney W. Grimes]

> The server uses a CF card in place of a hard disk. The server oddly enough is Windows 98 SE based. I have a CentOS 7 box with a USB CF card reader.
> I am trying to image the CF card and write the image to a second CF card. Kind of a, make a backup to experiment with scenario and use the backup.
> 
> This my CentOS 7 box doesn't work:
> 
> $ sudo dd if=/dev/sdb of=win98seQSP2predrivers.img bs=1M count=1000 status=progress
                                                     ^^^^^
> 
> The file created cannot be mounted. If you write it to another CF card, you get garbage.

Not all CF card respond well to large read or write requests, you may wish
to try, the much slower but almost certain to work, bs=512.

Also why are you using count?  Just let dd hit EOM (end of media).

I usually do "disk" type imaging of this type of stuff with bs=32768, most devices
seem to be ok with that.  If I get a bad image I go back to 512 and take the slow
road.

ALSO incase of errors, check your dmesg!  And use:
dd if=/dev/sdb of=XXX conv=noerror,sync bs=32k status=progress.

-- 
Rod Grimes                                                 rgrimes at freebsd.org