From owner-freebsd-questions@FreeBSD.ORG Thu Jun 30 13:02:37 2011 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id F0572106566C for ; Thu, 30 Jun 2011 13:02:37 +0000 (UTC) (envelope-from korvus@comcast.net) Received: from qmta12.westchester.pa.mail.comcast.net (qmta12.westchester.pa.mail.comcast.net [76.96.59.227]) by mx1.freebsd.org (Postfix) with ESMTP id 9BFB18FC0C for ; Thu, 30 Jun 2011 13:02:37 +0000 (UTC) Received: from omta16.westchester.pa.mail.comcast.net ([76.96.62.88]) by qmta12.westchester.pa.mail.comcast.net with comcast id 2C871h0011uE5Es5CCuS3p; Thu, 30 Jun 2011 12:54:26 +0000 Received: from [10.0.0.79] ([71.199.122.142]) by omta16.westchester.pa.mail.comcast.net with comcast id 2CuR1h00n34Sj4f3cCuRYB; Thu, 30 Jun 2011 12:54:26 +0000 Message-ID: <4E0C7208.2040805@comcast.net> Date: Thu, 30 Jun 2011 08:54:32 -0400 From: Steve Polyack User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.18) Gecko/20110616 Thunderbird/3.1.11 MIME-Version: 1.0 To: Daniel Feenberg References: <4E0B540B.3090400@comcast.net> <4e0c0548.eW27hshSLoLhhTu1%perryh@pluto.rain.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-net@freebsd.org, perryh@pluto.rain.com, freebsd-questions@freebsd.org Subject: Re: Question about NIC link state initialization X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 30 Jun 2011 13:02:38 -0000 On 6/30/2011 6:49 AM, Daniel Feenberg wrote: > > > On Wed, 29 Jun 2011, perryh@pluto.rain.com wrote: > >> Steve Polyack wrote: >> >>> ... An occaisional fat-finger in /etc/fstab may cause one to >>> end up in single-user mode ... some of these systems have a LOM >>> (lights-out management) controller which shares the system's >>> on-board NICs ... when the system drops out of init(8) and into >>> single-user mode, the links on the interfaces never come up, >>> and therefore the LOM becomes inaccessible. >>> >>> ... all one has to do is run ifconfig to cause the NIC's links to >>> come up ... why do we have to run ifconfig(8) to bring the links >>> up on the attached interfaces? >> >> When trying to troubleshoot a problem that was known or suspected to >> involve the network or its hardware, one might not _want_ the NICs > > Well, maybe, but if the system needs to boot into multi-user mode for > the LOM to be available, what is the need for the LOM? At that point > you can do everything you might need through the OS interface. Can I > ask what is the brand of this so-called LOM? Is there any > documentation implying something more useful? Do they describe doing a > bare metal install of an > OS? They are the Dell Remote Access Controllers (DRACs). Now, they do have their own dedicated NIC, which we use for anything that really needs the attention. However, the shared feature saves us a switchport per server we use it on. When both on-board NICs are cabled (i.e. for lagg(4) failover), then the DRAC's shared NIC mode *also* supports automatic failover between both on-board NICs. This doesn't help however if the operating system never turns on the links to either on-board NIC. I was able to "fix" the single-user mode behavior (which I agree, isn't necessarily broken) and get it to bring up the links by simply patching init(8) to call system("/sbin/ifconfig") before prompting for the single-user shell. It works, but I feel dirty. - Steve