dd question

Warren Block wblock at wonkity.com
Sun Sep 27 11:46:28 UTC 2015

On Sun, 27 Sep 2015, Polytropon wrote:

> On Sat, 26 Sep 2015 19:37:51 -0453.75, William A. Mahaffey III wrote:
>> Update: I tried the dd again w/ 'bs=1m' & it worked much faster:
> It's a more "native" block size suited for the devices in question.
> 512 blocks aren't much common anymore.

It's not really about the native block size of the device, but the 
overhead.  Copying 1M with the default blocksize takes 2,048 
transactions.  Setting bs=1M does it in only one.  It works the same 
with spinning disks, although the buffer does not need to be as large. 
Usually 64K or 128K is enough there.

Incidently, the Handbook installation chapter does show the right way to 
install image files.

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