From owner-freebsd-hackers Mon Aug 16 15:53:37 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from dingo.cdrom.com (dingo.cdrom.com [204.216.28.145]) by hub.freebsd.org (Postfix) with ESMTP id F1C7215902 for ; Mon, 16 Aug 1999 15:53:34 -0700 (PDT) (envelope-from mike@dingo.cdrom.com) Received: from dingo.cdrom.com (localhost.cdrom.com [127.0.0.1]) by dingo.cdrom.com (8.9.3/8.8.8) with ESMTP id PAA01394; Mon, 16 Aug 1999 15:47:45 -0700 (PDT) (envelope-from mike@dingo.cdrom.com) Message-Id: <199908162247.PAA01394@dingo.cdrom.com> X-Mailer: exmh version 2.0.2 2/24/98 To: Andrzej Bialecki Cc: freebsd-hackers@freebsd.org Subject: Re: Saving system image to disk (NOT on a laptop) In-reply-to: Your message of "Tue, 17 Aug 1999 00:38:52 +0200." Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Mon, 16 Aug 1999 15:47:45 -0700 From: Mike Smith Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > Hi, > > To all you low-level kernel and bootloader hackers: what would it take to > save and restore a running system image (presumably from dedicated raw > partition) so that the system would continue where it left before reboot? > > It doesn't sound that difficult to me - after all, laptops somehow do it - > but I know too little low-level stuff to try implementing it myself... It's quite difficult, in that it requires intimate low-level knowledge of the hardware in order to save/restore its state correctly. In the case of laptops it's much easier because the hardware can't be changed under the image, and the BIOS knows all about the hardware. To do it "right" in the generic case, you'd virtually have to go through the entire boot process again. It might make more sense to try an alternative arrangement whereby you paged _everything_ out to swap, then saved the entire kernel data and bss segments somewhere. You'd have fun at the restore's cutover point though, and any stateful hardware would still be a bitch to deal with. -- \\ The mind's the standard \\ Mike Smith \\ of the man. \\ msmith@freebsd.org \\ -- Joseph Merrick \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message