From owner-freebsd-questions@FreeBSD.ORG Sat Aug 27 13:18:23 2011 Return-Path: Delivered-To: questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 582411065670 for ; Sat, 27 Aug 2011 13:18:23 +0000 (UTC) (envelope-from wblock@wonkity.com) Received: from wonkity.com (wonkity.com [67.158.26.137]) by mx1.freebsd.org (Postfix) with ESMTP id 11FC48FC13 for ; Sat, 27 Aug 2011 13:18:22 +0000 (UTC) Received: from wonkity.com (localhost [127.0.0.1]) by wonkity.com (8.14.5/8.14.5) with ESMTP id p7RDIKVd004925; Sat, 27 Aug 2011 07:18:20 -0600 (MDT) (envelope-from wblock@wonkity.com) Received: from localhost (wblock@localhost) by wonkity.com (8.14.5/8.14.5/Submit) with ESMTP id p7RDIKdN004922; Sat, 27 Aug 2011 07:18:20 -0600 (MDT) (envelope-from wblock@wonkity.com) Date: Sat, 27 Aug 2011 07:18:20 -0600 (MDT) From: Warren Block To: Johan Hendriks In-Reply-To: <6C3F8332272B7D4DA26909F15F1C90E1E5B722@SRV01.double-l.local> Message-ID: References: , <6C3F8332272B7D4DA26909F15F1C90E1E5B722@SRV01.double-l.local> User-Agent: Alpine 2.00 (BSF 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; format=flowed; charset=US-ASCII X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.7 (wonkity.com [127.0.0.1]); Sat, 27 Aug 2011 07:18:20 -0600 (MDT) Cc: Adam Vande More , "questions@freebsd.org" Subject: RE: glabel, gmirror, and gpart 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: Sat, 27 Aug 2011 13:18:23 -0000 On Sat, 27 Aug 2011, Johan Hendriks wrote: >> On Fri, Aug 26, 2011 at 11:04 PM, Warren Block wrote: > >> So it's cosmetic, but not really the kind of message that instills >> confidence. gptboot needs to be able to tell if it's reading from a >> gmirror. Or gmirror should provide one block less than it does, so it >> doesn't overwrite the GPT backup. > > I use the whole disk to gmirror setup on all my servers. > > And one day i thought i could try the gpart stuff. > I also saw the message at startup, and disgarded it. > This was on 8.1 > > But when i did an upgrade to 8.2 later on, the system could not boot. > So i had to find another way. > > So i would not do it like you do now, it could turn against you in the long run. > The thing i did was to mirror each partition. > Like so http://unix-heaven.org/node/24 > that way it worked. > Do not forget to make your second disk bootable also That was the idea I had last night trying to go back to sleep. Use gpart to partition the disks, and use gmirror to mirror the partitions. A little more setup, because you have to create multiple mirrors instead of one with partitions inside it. It also addresses Adam's question. For two dissimilar disks, create partitions of the same size and mirror them instead of the whole disk. gmirror apparently doesn't keep a list of outstanding writes, so smaller mirrors should be faster to sync.