From owner-freebsd-current@FreeBSD.ORG Fri Oct 7 18:54:46 2011 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id B5B161065672 for ; Fri, 7 Oct 2011 18:54:46 +0000 (UTC) (envelope-from kaduk@mit.edu) Received: from dmz-mailsec-scanner-6.mit.edu (DMZ-MAILSEC-SCANNER-6.MIT.EDU [18.7.68.35]) by mx1.freebsd.org (Postfix) with ESMTP id 547E58FC0C for ; Fri, 7 Oct 2011 18:54:45 +0000 (UTC) X-AuditID: 12074423-b7f756d0000008d0-2f-4e8f4af578bc Received: from mailhub-auth-3.mit.edu ( [18.9.21.43]) by dmz-mailsec-scanner-6.mit.edu (Symantec Messaging Gateway) with SMTP id 0A.D6.02256.5FA4F8E4; Fri, 7 Oct 2011 14:54:45 -0400 (EDT) Received: from outgoing.mit.edu (OUTGOING-AUTH.MIT.EDU [18.7.22.103]) by mailhub-auth-3.mit.edu (8.13.8/8.9.2) with ESMTP id p97IsiIx000757; Fri, 7 Oct 2011 14:54:44 -0400 Received: from multics.mit.edu (MULTICS.MIT.EDU [18.187.1.73]) (authenticated bits=56) (User authenticated as kaduk@ATHENA.MIT.EDU) by outgoing.mit.edu (8.13.6/8.12.4) with ESMTP id p97Isgbt020733 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT); Fri, 7 Oct 2011 14:54:43 -0400 (EDT) Received: (from kaduk@localhost) by multics.mit.edu (8.12.9.20060308) id p97Iscnt016190; Fri, 7 Oct 2011 14:54:38 -0400 (EDT) Date: Fri, 7 Oct 2011 14:54:37 -0400 (EDT) From: Benjamin Kaduk To: Warren Block In-Reply-To: Message-ID: References: <80750.1318010551@critter.freebsd.dk> User-Agent: Alpine 1.10 (GSO 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFupmleLIzCtJLcpLzFFi42IR4hTV1v3q1e9nMPemjMWcNx+YLHbdOcNs 8eEbv8WvUx4OLB4zPs1n8dg56y67x6f9k9k8jnQ8YgxgieKySUnNySxLLdK3S+DK+LRrO2PB U56KS38PMDcwfufsYuTkkBAwkXh79RALhC0mceHeerYuRi4OIYF9jBLfltxjgXDWM0pc/PWP CcLZzyTx4elJNpAWIYF6iTl9F1lBbBYBLYmfV7YygdhsAioSM99sBKrh4BARUJXYe8YaJMws UCoxa/8BsFZhAQuJB2eWM4PYnAK2EuuPdoCN4RWwl7jadIQRYtcNRolVpzaBnScqoCOxev8U FogiQYmTM5+wQAy1lDj35zrbBEbBWUhSs5CkFjAyrWKUTcmt0s1NzMwpTk3WLU5OzMtLLdI1 08vNLNFLTSndxAgKZ3YX5R2Mfw4qHWIU4GBU4uGd9bTXT4g1say4MvcQoyQHk5Io7yfPfj8h vqT8lMqMxOKM+KLSnNTiQ4wSHMxKIrwOb/r8hHhTEiurUovyYVLSHCxK4rwyOx38hATSE0tS s1NTC1KLYLIyHBxKErymwLgVEixKTU+tSMvMKUFIM3FwggznARr+GWQxb3FBYm5xZjpE/hSj LsfTnRNOMgqx5OXnpUqJ8zqCDBIAKcoozYObA0tDrxjFgd4S5jUEqeIBpjC4Sa+AljABLTlt DLakJBEhJdXAGMC0IqR60p2g12/eLO5o67l8cZlNUXf32bbm4NL2ZJ7g5yZ9++9bC2luCg22 tOx18bqWmBswdRXvIxXdONEYPwujY6EbNR6t93l+xPWSPldiSqnK86Uxgv118SFFx9hnOzmL 86z8UP6/Y8Jsu3dL9jJe2eHyZdnrvfVbajo7pqXNTT1eVLFaiaU4I9FQi7moOBEA6dgdiB4D AAA= Cc: Poul-Henning Kamp , freebsd-current@freebsd.org, Arnaud Lacombe Subject: Re: aliasing (or renaming) kern.geom.debugflags X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 07 Oct 2011 18:54:46 -0000 On Fri, 7 Oct 2011, Warren Block wrote: > On Fri, 7 Oct 2011, Arnaud Lacombe wrote: > >> Hi, >> >> On Fri, Oct 7, 2011 at 2:13 PM, Warren Block wrote: >>> On Fri, 7 Oct 2011, Poul-Henning Kamp wrote: >>> >>>> In message , Benjamin >>>> Kaduk >>>> writes: >>>> >>>>> Now, an ordinary user who is >>>>> doing this for the first time might ask, "why do I need to do something >>>>> with 'debugflags' in order to make a USB stick? >>>> >>>> Which is the exactly right question to ask. >>>> >>>> The procedure documented is clearly flawed. >>> >>> Probably a misunderstanding on my part, since I suggested it to Glen. >>> Can't >>> recall the circumstances exactly. >>> >>> The next question would be: what is the correct procedure? >>> >> I'd guess the procedure involves shooting your feet: >> >> from `sys/geom/geom_subr.c': >> >> /* If foot-shooting is enabled, any open on rank#1 is OK */ >> if ((g_debugflags & 16) && pp->geom->rank == 1) >> ; > > Well, yes. The goal is to unprotect the device, regardless of what may > already be on it. Then the user can overwrite it with the memory stick > image. > > The current documentation is > > sysctl kern.geom.debugflags=16 > dd if=memstick.img of=/dev/whatever0 bs=64k I presume that Poul-Henning was not claiming that the documentation did not match the functional procedure, but rather that the procedure needed to achieve the goal (of a functional USB stick) is flawed. (Even if it is correctly documented.) -Ben