docs/119386: bsdlabel and newfs on DVD-RAM (handbook ch. 18.7.9)

[Marc Fonvieille]

The following reply was made to PR docs/119386; it has been noted by GNATS.

From: Marc Fonvieille <blackend at FreeBSD.org>
To: Martin Laabs <martin.laabs at mailbox.tu-dresden.de>
Cc: freebsd-gnats-submit at FreeBSD.org
Subject: Re: docs/119386: bsdlabel and newfs on DVD-RAM (handbook ch.
	18.7.9)
Date: Sun, 6 Jan 2008 20:17:55 +0100

 On Sun, Jan 06, 2008 at 03:36:45PM +0000, Martin Laabs wrote:
 > 
 > >Description:
 > In chapter 18.7.9 of the handbook (Using a DVD-RAM) is a description how to use/prepare a DVD-RAM so that it can be used with freebsd. Therefore you have to use bsdlabel and newfs.
 > Since the blocksize of an DVD-RAM ist 2048 byte and bsdlabel and newfs (also with the -s 2048 option) do at least one write with blocksize smaller than 2048 byte both commands fails.
 > 
 > >How-To-Repeat:
 > For example the first command, which is "dd if=/dev/zero of=/dev/acd0 count=2", produces the following output on my system (Optiarc DVD RW AD-7170A/1.02 device)
 > 
 > su:~$ dd if=/dev/zero of=/dev/acd0 count=2
 > dd: /dev/acd0: Invalid argument
 > 1+0 records in
 > 0+0 records out
 > 0 bytes transferred in 0.000138 secs (0 bytes/sec)
 > 
 > If I add the bs=2k option it works fine:
 > 
 > su:~$ dd if=/dev/zero of=/dev/acd0 count=1 bs=2k
 > 1+0 records in
 > 1+0 records out
 > 2048 bytes transferred in 0.001740 secs (1177026 bytes/sec)
 
 So:
 
 # dd if=/dev/zero of=/dev/acd0 bs=2k count=1
 # bsdlabel -Bw acd0
 # newfs /dev/acd0
 
 is enough? (I can't test, I don't have any DVD-RAM writer under the
 hand)
 
 -- 
 Marc