[Bug-ddrescue] Question & suggestion

[ddrescue.admin]

Question...
I am trying to rescue a drive (120GB) which has large blocks of errors then
blocks of readable data. What I want to do is to try and read a large block
(1MB) of data, if it fails then skip on by 1MB and try again.  So I launched
ddrescue with -c 1024 (which should read 512K chunks as I understand it).
But I am not seeing what I expect in syslog, I would expect to see failed to
read sector @ n, followed by failed to read sector @ n+1024 in the error
areas, but the sector numbers go up by varying amounts, sometimes only a few
10's of sectors. It showing 40+minutes since last successful read so it
doesn't seem to be reading any good data (or is that the last time an entire
block was read without error?).

In fact would an option to say skip on by 'x' if you get more than 'y'
consecutive read failures be a good idea? Eg for this drive I might skip on
by 100MB or so...

Suggestion
Where a source drive goes offline during recovery is it possible to identify
this from the returned error code and abort ddrescue, rather than filling
the log up with failed sectors?  EG on IDE I got DID_Invalid & on usb I get
drive offline.  I think the logic should be 'media error code' carry on,
device / drive error 'abort'...

Thanks for a useful tool!

David Mitchell