From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bill Davidsen Subject: Re: RAID1, hot-swap and boot integrity Date: Fri, 02 Mar 2007 15:57:14 -0500 Message-ID: <45E88FAA.5020106@tmr.com> References: <45E82EF8.9000106@laurelnetworks.com> <20070302161004.GE31010@boogie.lpds.sztaki.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20070302161004.GE31010@boogie.lpds.sztaki.hu> Sender: linux-raid-owner@vger.kernel.org To: Gabor Gombas Cc: Mike Accetta , linux-raid@vger.kernel.org List-Id: linux-raid.ids Gabor Gombas wrote: > On Fri, Mar 02, 2007 at 09:04:40AM -0500, Mike Accetta wrote: > > >> Thoughts or other suggestions anyone? >> > > This is a case where a very small /boot partition is still a very good > idea... 50-100MB is a good choice (some initramfs generators require > quite a bit of space under /boot while generating the initramfs image > esp. if you use distro-provided "contains-everything-and-the-kitchen-sink" > kernels, so it is not wise to make /boot _too_ small). > You are exactly right on that! Some (many) BIOS implementations will read the boot sector off the drive, and if there is no error will run the boot sector. > But if you do not want /boot to be separate a moderately sized root > partition is equally good. What you want to avoid is the "whole disk is > a single partition/file system" kind of setup. > > Actually, the solution is moderately simple, install the replacement drive, create the partitions, and **don't mark the boot partition active** until the copy is complete. The BIOS will boot from the 1st active partition it finds (again, in sane cases). I never have anything changing in /boot in normal operation, so I admit to using dd to do a copy with the array stopped. No particular reason to think it works better than just a rebuild. After the partition is valid I set the active flag in the partition. -- bill davidsen CTO TMR Associates, Inc Doing interesting things with small computers since 1979