@samp{w}=2, @samp{x@var{m}}=@var{m}, or any of the
standard block size suffixes like @samp{k}=1024 (@pxref{Block size}).
+Any block size you specify via @samp{bs=}, @samp{ibs=}, @samp{obs=}, @samp{cbs=}
+should not be too large---values larger than a few megabytes
+are generally wasteful or (as in the gigabyte..exabyte case) downright
+counterproductive or error-inducing.
+
Use different @command{dd} invocations to use different block sizes for
skipping and I/O@. For example, the following shell commands copy data
in 512 KiB blocks between a disk and a tape, but do not save or restore a