I'm new to this mailing list thing so if I stuff up in my reply I would like to apologise in advance :D
On 21 September 2010 19:12, Antonio Diaz Diaz <[email protected]> wrote: > Hello Reon, > > > Reon Toerien wrote: > >> Is it possible to do a reverse image starting at the last block and >> jumping >> further back when bad blocks are encountered until block zero is reached? >> In >> other words everything works in reverse. >> > > Currently not. When trimming backwards a block, ddrescue marks this block > for later splitting as soon as the first bad sector is found. > > Reading in reverse a sector at a time is very slow (less than 100kB/s. One > month to read a 250GB disc). This is why ddrescue currently uses it only to > trim bad blocks. > > > > If not could it be added as a feature request? >> > > Of course. :-) > > > > Should help eliminate the read ahead cache on the drive where it reads >> 16MB >> ahead in a area that has bad sectors. >> > > I guess it won't be simple. Does reading in reverse help if the drive is > dumb enough that it always tries to read ahead forgetting previous failures? > The cache is still used but only populated with what has already been read > > What pass (copy, split, retry, all) would be more useful to run in reverse? > I'll leave that to you and the rest of the clever people over here :) > > I am sure the wonderful people in this list will help find the most useful > behaviour to implement in ddrescue 1.14. Thanks in advance for your > feedback. :-) > I'm sure they will. > > > Regards, > Antonio. > -- Kind Regards Reon Toerien
_______________________________________________ Bug-ddrescue mailing list [email protected] http://lists.gnu.org/mailman/listinfo/bug-ddrescue
