Skip site navigation (1)Skip section navigation (2)
Date:      Tue, 6 Dec 2011 14:09:48 +0100
From:      Patrick Lamaiziere <patfbsd@davenulle.org>
To:        Dan Nelson <dnelson@allantgroup.com>
Cc:        FreeBSD <freebsd-questions@freebsd.org>
Subject:   Re: Command which does not work anymore?
Message-ID:  <20111206140948.08e5af9d@mr129166>
In-Reply-To: <20111205173845.GA53453@dan.emsphone.com>
References:  <20111205105130.161fc78a@mr129166> <20111205173845.GA53453@dan.emsphone.com>

next in thread | previous in thread | raw e-mail | index | archive | help
Le Mon, 5 Dec 2011 11:38:46 -0600,
Dan Nelson <dnelson@allantgroup.com> a écrit :

Hello,

> dd with a bs= option tells dd to use read() syscalls with a 10mb
> size, but ssh is going to feed it data in much smaller chunks, and
> they're unlikely to be multiples of a disk block in size (which you
> have to use if you are writing directly to a raw disk device).  The
> "0+5 records in/0+4 records out" lines say that dd read 5 blocks of
> data (but they were less than 10mb), and wrote 4 blocks (again less
> than 10mb).  Try using a smaller blocksize (8k or 4k), or use a
> buffering program like ports/misc/team or misc/buffer just in front
> of your dd command, so that dd always sees block-sized writes from
> its stdin stream.
> 
> If that command worked in 8.2, it was just by accident.

Ah ok! Thanks a lot for the explanation.

Regards.



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20111206140948.08e5af9d>