From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([208.92.234.80] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1S1OUk-0002mW-C6 for garchives@archives.gentoo.org; Sat, 25 Feb 2012 20:45:30 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id A05D1E0C1F; Sat, 25 Feb 2012 20:45:15 +0000 (UTC) Received: from mail-ee0-f53.google.com (mail-ee0-f53.google.com [74.125.83.53]) by pigeon.gentoo.org (Postfix) with ESMTP id 1F9F2E0A6E for ; Sat, 25 Feb 2012 20:44:09 +0000 (UTC) Received: by eekb47 with SMTP id b47so706970eek.40 for ; Sat, 25 Feb 2012 12:44:09 -0800 (PST) Received-SPF: pass (google.com: domain of robert.david.public@gmail.com designates 10.14.133.10 as permitted sender) client-ip=10.14.133.10; Authentication-Results: mr.google.com; spf=pass (google.com: domain of robert.david.public@gmail.com designates 10.14.133.10 as permitted sender) smtp.mail=robert.david.public@gmail.com; dkim=pass header.i=robert.david.public@gmail.com Received: from mr.google.com ([10.14.133.10]) by 10.14.133.10 with SMTP id p10mr1421978eei.36.1330202649365 (num_hops = 1); Sat, 25 Feb 2012 12:44:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:in-reply-to:references:x-mailer :mime-version:content-type:content-transfer-encoding; bh=9mbnSzUfqw4hfJqlIATc/0oN0N+rKBB0rtMhL9+O9oU=; b=biRtAI8DUjZchZ37sRVN2co3d7hP0e40QLwHIR6tu3QQ6VUYlNJ6xn72oTE6gXix0v ldY23P9eiv9Ebs+OHBSD6jbxDaUXPtiG5gZSeBZzwX8hJbn2tUQlctkqO+N58XZN+XFx Bk0ZesS9jV2aFBPXUugucpZiftMzE7CZelDT4= Received: by 10.14.133.10 with SMTP id p10mr1051511eei.36.1330202649252; Sat, 25 Feb 2012 12:44:09 -0800 (PST) Received: from localhost (gate.chabry.cz. [80.92.246.13]) by mx.google.com with ESMTPS id o49sm35896781eeb.7.2012.02.25.12.44.08 (version=SSLv3 cipher=OTHER); Sat, 25 Feb 2012 12:44:08 -0800 (PST) Date: Sat, 25 Feb 2012 21:44:04 +0100 From: Robert David To: gentoo-user@lists.gentoo.org Cc: pandu@poluan.info, emailgrant@gmail.com Subject: Re: [gentoo-user] Re: Safe way to test a new kernel? Message-ID: <20120225214404.5e7c6a73@gmail.com> In-Reply-To: References: <20120225095751.7ad3d9d6@gmail.com> <20120225200305.2e9ae382@gmail.com> X-Mailer: Claws Mail 3.7.10 (GTK+ 2.24.8; x86_64-pc-linux-gnu) Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Archives-Salt: 96feb46f-9507-436c-9eea-ff6a81252394 X-Archives-Hash: 0f8fa09b0af67784ba5d4cd06f827eea V Sun, 26 Feb 2012 02:50:46 +0700 Pandu Poluan naps=C3=A1no: > On Feb 26, 2012 2:05 AM, "Robert David" > wrote: > > > > V Sat, 25 Feb 2012 10:32:20 -0800 > > Grant naps=C3=A1no: > > > > > >> >> I need to test a kernel config change on a remote system. > > > >> >> Is there a safe way to do this? The fallback thing in grub > > > >> >> has never worked for me. When does that ever work? > > > >> > > > > >> > > > > >> > You can press ESC in the Grub screen and it will take you to > > > >> > text-only mode. There, you select an entry, press "e" and > > > >> > edit it. Press ENTER when you're finished, and then press > > > >> > "b" to boot your modified entry. > > > >> > > > > >> > That way, you can boot whatever kernel you want if the > > > >> > current one doesn't work. > > > >> > > > >> I can't do that remotely though. I'm probably asking for > > > >> something that doesn't exist. > > > >> > > > >> - Grant > > > >> > > > > > > > > Don't do that if you don't have some tool like KVM, or other > > > > remote management of the server. Or if it is available in the > > > > data center, just call them and order this service for the time > > > > you need to do updates. > > > > > > > > This is why I don't use gentoo on servers any more, just because > > > > I rather stay safe than sorry. > > > > > > How is another distro different in this situation? > > > > > > - Grant > > > > Just because when using distros like Centos/RHEL or Debian stable, > > you have very little chance that the kernel released will fail. Due > > to extensive testing, user base and update policy. And major kernel > > update you done only once in few years and the transition is tested > > before release done (though you are supposed to test yourself to be > > safe). > > > > This is not saying that gentoo is bad, I'm very big fan of gentoo. > > But you have to concern where it use and where not. > > > > Robert. > > >=20 > Anecdotal, but... >=20 > I once had an Ubuntu VM that can't shutdown after a kernel update. > First boot after update went well, but when I rebooted it again, it > pegged its vCPUs at 100% before I ordered the Xen hypervisor to put > it out of its misery. I don't want to start flame, but ubuntu was never a system for server for me. It may be good for desktop, but not server. For me ubuntu is too up-to-date to be a good server distro, even the LTS is not something well done, maybe in version x.x.3-4 of LTS it s reasonable to put on server, but it will soon end with support. So nothing for me. >=20 > The bug was apparently in the portion of the kernel running in the > primary CPU that's responsible for shutting down the other CPUs > before cutting the power. And IIRC, this bug affects all > multi-processor configuration. >=20 > So, as you can see, binary distros can still fuck up royal time. Not > to mention that if you have an exotic configuration, support for your > configuration might not be built into the kernel by the distro. >=20 This is true, but you cannot compare countless options that gentoo can be configured with few options that binary distro is capable and thus more probably tested before. > Somehow I believe people deploying Gentoo servers will be much more > careful... Agree. But real word is not so ideal. I got situations where I need upgrade basic gentoo server to more special virtualized environment. Just a customer wanted that. This consist about changing net to bridge, add/update kernel modules, etc. I ended with bricked server after a long checks etc, so I have to check the server physicaly. I did another thing in debian remotely within a half hour. This also implies that I'm not so good admin, but things happen not so good as you expect every time. I still use gentoo on my notebook and work computer, or specialized project where it benefits. But all the servers are migrated to debian or centos. I just don't have so much time to play. =20 Robert. >=20 > Rgds, =20