ddrescue, range in multiples of bytes

Question

When using ddrescue, is it possible to only specify the first 25Gio? I see that I can use the -i parameter with block sizes, but can this be specified with Gio directly?;)

Answer 1

According to the manual -i takes bytes. Then the manual states:

Numbers given as arguments to options (positions, sizes, rates, etc) may be expressed as decimal, hexadecimal, or octal values (using the same syntax as integer constants in C++), and may be followed by a multiplier and an optional B for "byte". […]

There is a table which states Gi is a valid prefix for gibibyte, so -i 25GiB is valid.

But note -i is not what you want.

-i bytes
--input-position=bytes

Starting position of the rescue domain in infile, in bytes. Defaults to 0. […]

To only specify the first 25Gio, you should use -s 25GiB (and the default value of -i). This is what -s means:

-s bytes
--size=bytes

Maximum size of the rescue domain in bytes. […]