From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by finch.gentoo.org (Postfix) with ESMTPS id 95F031382C5 for ; Sat, 19 Dec 2020 18:55:57 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 94A2BE097A; Sat, 19 Dec 2020 18:55:52 +0000 (UTC) Received: from smtp.hosts.co.uk (smtp.hosts.co.uk [85.233.160.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 41680E093D for ; Sat, 19 Dec 2020 18:55:51 +0000 (UTC) Received: from host86-149-69-253.range86-149.btcentralplus.com ([86.149.69.253] helo=[192.168.1.65]) by smtp.hosts.co.uk with esmtpa (Exim) (envelope-from ) id 1kqhOP-0003aV-4w for gentoo-user@lists.gentoo.org; Sat, 19 Dec 2020 18:55:49 +0000 Subject: Re: [gentoo-user] Rearranging hard drives and data. To: gentoo-user@lists.gentoo.org References: <20201219170616.0998108c@digimed.co.uk> <091cc36b-c7ab-26ce-1e1c-f1a3bc20a294@gmail.com> From: antlists Message-ID: <37f509ee-491e-045d-a840-e53d7d41a078@youngman.org.uk> Date: Sat, 19 Dec 2020 18:55:50 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.5.1 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 X-Auto-Response-Suppress: DR, RN, NRN, OOF, AutoReply MIME-Version: 1.0 In-Reply-To: <091cc36b-c7ab-26ce-1e1c-f1a3bc20a294@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 8bit X-Archives-Salt: c9203316-beed-4074-b4da-a37f6c5bfcf0 X-Archives-Hash: e81b96062b69fd8ae8c2227542a0b01c On 19/12/2020 17:32, Dale wrote: > Neil Bothwick wrote: >> On Sat, 19 Dec 2020 07:02:23 -0600, Dale wrote: >> >>> I have another question related to LVM.  Let's say a system crashes and >>> dies.  Or I just move a drive, or drives, with LVM on it to another >>> system.  Does the system just recognize the drives and knows how to add >>> them or do I have to do that manually on the new system? >> It should just work if you move all the PVs in the volume group. One >> thing to watch out for is if the destination system is already using LVM, >> the volume groups must be named differently. That's why I always use >> unique VG names based on the hostname. >> > > Ahhh, so it stores the info on the drive so that it knows what it is. > Neato!!  I was thinking it was in /etc/lvm/ or something.  I've wondered > about that for a while now. mdadm version 0 stored its information in mdadm.conf. That was a mistake - it had the downside you couldn't boot from the array, it was wide open to errors, arrays were regularly trashed because things had got confused, etc etc. Sticking all the necessary information in a superblock is now considered must-do good practice. > > Naming them based on hostname is also a good idea.  I don't have mine > named that way but if I ever redo them, I will.  It could save me some > problems down the road. > Again, that's now the default for mdadm - not necessarily the user name, but the internal array name is something like "tigger:0", to quote one of mine - array 0 created on tigger. Cheers, Wol