Re: [Bug-ddrescue] how to rescue floppy disks?

[fctk86]

Antonio Diaz Diaz wrote:
> fctk86 wrote:
> > i'm using ddrescue-1.7 in order to backup lots of old 3.5" floppy 
> > disks and i'd like to make the process as efficient as possible.
>
> In my system the fastest settings when reading from error free discs 
> with ddrescue-1.8 are "-b1024" for 5 1/4" 360k floppies and "--direct" 
> for 3.5" 1.44M. (All other values set to default ones).
>
> In case of read errors it may be faster to set --cluster-size to a 
> smaller value, the number of sectors in a track for example.
>
> But of course, your system may behave differently. Doing some testing 
> won't hurt.
>
>
> > i'm asking because the info manual says a little different thing:
>
> I'll clarify the manual to differentiate between 360k and 1.44M floppies.
>
>
> Regards,
> Antonio.

i just made some testing. here you are the results.

using the --direct option is a lot better than not using it, for the 
following two reasons:
- the reading process is much faster (96 seconds instead of 139, 65 
seconds instead of 159, ...)
- the final errsize is smaller (2048 B instead of 16384 B, 512 B instead 
of 4096, ...); the number of errors instead is the same (4 in the first 
case, only 1 in the second, ...)

using -c 18 or -c 9 seems to further improve speed (10 to 40 second less 
for floppy).

all tests were run with the -b 512 option, that is the smallest block 
size i can set for reading floppy disks.

i haven't done tests with 5.25" floppy disks yet.

please let me know what you think.

thanks.