[Bug 247136] Handbook, section 2.3.1.1: dd(1) command uses "bs=1M" (slow), should be "bs=4k" (/much/ faster)

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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=247136

andrew at tao11.riddles.org.uk changed:

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                 CC|                            |andrew at tao11.riddles.org.uk

--- Comment #1 from andrew at tao11.riddles.org.uk ---
My experience and benchmarks differ - from a freebsd stable/11 system to a
random USB2 thumb drive, I get a slowdown on the order of 8x from using 4k
rather than 64k block size.

Block sizes of 64k, 128k, 256k, 1m give me indistinguishable speeds (note,
there is basically no reason to ever use a blocksize greater than MAXPHYS when
writing to a raw device, and that is 128k in standard builds). All block sizes
below 64k are slower for me.

status=progress is not needed on freebsd since you can always just use
control-T.

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