From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-qk0-f174.google.com ([209.85.220.174]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1ce7UP-0006cp-Aq for kexec@lists.infradead.org; Wed, 15 Feb 2017 21:51:57 +0000 Received: by mail-qk0-f174.google.com with SMTP id p22so73397705qka.0 for ; Wed, 15 Feb 2017 13:51:31 -0800 (PST) Received: from hops.home (pool-100-0-1-34.bstnma.fios.verizon.net. [100.0.1.34]) by smtp.gmail.com with ESMTPSA id 23sm3121030qtp.20.2017.02.15.13.45.10 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 15 Feb 2017 13:45:11 -0800 (PST) Subject: Re: kexec on panic References: <52a88de81ea3c62bb2be9e222eb85805@nuclearcat.com> <20170210164313.5fe98b75@hananiah.suse.cz> <864d8c8b-4573-9915-e164-aee5f1dd014b@clifhouck.com> From: Marc Milgram Message-ID: <7455e38d-cdf8-df93-2d8d-027ebf744c51@redhat.com> Date: Wed, 15 Feb 2017 16:45:10 -0500 MIME-Version: 1.0 In-Reply-To: <864d8c8b-4573-9915-e164-aee5f1dd014b@clifhouck.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: kexec@lists.infradead.org It is possible to boot into a new kernel as documented on the following page: https://access.redhat.com/discussions/682993 That said, even though this is documented on a Red Hat page, Red Hat does not officially support it. Marc On 02/15/2017 12:29 PM, Clif Houck wrote: > Is it possible to kexec on demand (not panic!) into another kernel with > the idea being to avoid a reboot? > > For instance, say you had Linux running in a ramdisk, and all that > ramdisk Linux did was lay down a bootable Linux image onto the main > disk, and then awaited a command to kexec to the Linux image on disk? Is > something like that possible? Would I still need to specially craft the > initrd? If so, is there any literature available on how to do that? > > Thanks, > Clif Houck > > On 2/10/2017 9:43 AM, Petr Tesarik wrote: >> On Fri, 10 Feb 2017 10:14:02 +0200 >> Denys Fedoryshchenko wrote: >> >>> Hello, >>> >>> After years of using kexec and recent unpleasant experience with modern >>> (supposed to be blazing fast to boot) hardware that need 5-10 minutes >>> just to pass POST tests, >>> one question came up to me: >>> Is it possible anyhow to execute regular (not special "panic" one to >>> capture crash data) kexec on panic to reduce reboot time? >> >> No. But you can load a specially crafted panic initrd which kexec's >> back to the production kernel. >> >> HTH, >> Petr T >> >> _______________________________________________ >> kexec mailing list >> kexec@lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/kexec >> > > _______________________________________________ > kexec mailing list > kexec@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec > _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec