partclone will generate a domain mapfile for use with ddrescue using the --domain option. Like any tool that does this, it will only succeed if the block bitmap is intact and readable.
Robert Trevellyan On Tue, Jan 9, 2018 at 5:21 AM, Peter Clifton <p...@xev-power.com> wrote: > > > > > > > > > > > > > > > > > Domain mapfiles can be used for both purposes. You need a > separate tool to generate mapfiles containing the sectors accessible > through each head. Then, get the sector map of the desired files using > another utility (in mapfile format), and finally combine the mapfiles using > the ddrescuelog command. > > > > > > > > > It would be probably best to automate this using some wrapper (with > a GUI or curses-based interface). It's definitely beyond the scope of > ddrescue itself. > > > > Thanks for the reply. As the recovery progressed it became apparent that > the LBA to physical mapping is quite complex. I suspect the proprietary > recovery tools use manufacturer specific (and undocumented) ata commands / > serial port debug to extract this information from the drive). > > Do you happen to know of any recipes to extract filesystem block usage in > mapfile format? I couldn't find anything existing, but don't want to > re-invent a new utility. > > My thinking so far... > > ntfsclone allows a meta-data only clone of an NTFS volume into a sparse > file. Assuming it can read the meta-data blocks, this sparse file should > match the layout of the metadata blocks - although I'm not certain whether > this includes any indirect blocks (zfs terminology?) or bitmaps locating > all the user file data. (I'm no expert on the NTFS layout). > > The next step might be to write a utility which implements a data-source > for ntfsclone which overlays the sparse image of metadata (so the clone > utility "sees" the filesystem), whilst constructing an extent map of all > reads made whilst making a full clone. This extent map could then be used > to feed ddrescue. > > Peter > _______________________________________________ > Bug-ddrescue mailing list > Bug-ddrescue@gnu.org > https://lists.gnu.org/mailman/listinfo/bug-ddrescue > _______________________________________________ Bug-ddrescue mailing list Bug-ddrescue@gnu.org https://lists.gnu.org/mailman/listinfo/bug-ddrescue