opencoff/fastdd

Support multiple output files

raymondsteers opened this issue · 1 comments

Is it possible to support writing to multiple output files at once the way dcfldd does?

fastdd if=my.iso of=my2.iso of=my3.iso of=my4.iso

In testing, copying a single file with fastdd is much faster than dcfldd, however if you want to copy a single source file to 3 external backup USB disks (the use case in mind), you have to do that in a series of 3 commands using fastdd but can be done with a single command using dcfldd. If the source file in question is small enough to fit into cache mem then the 2nd and 3rd copies are extremely fast only limited by the write speed of the target drives, but as soon as you want to do this with something like a 40G source file, then dcfldd is much faster. It would be nice to have the best of both worlds.

You might mean fastdd if=my.iso of=out0.iso out1.iso out2.iso ...
Passing of multiple times would be weird.
Also, writing multiple files, means it shall be done in parallel, which doesn't seems to be an easy approach and if first writing fails for a certain reason, others may not, which would bring another issue. For now, you can just copy and paste output file to the targeted path.