From owner-freebsd-stable Wed Sep 15 18:47:58 1999 Delivered-To: freebsd-stable@freebsd.org Received: from public.bta.net.cn (public.bta.net.cn [202.96.0.97]) by hub.freebsd.org (Postfix) with ESMTP id 78A59152A1 for ; Wed, 15 Sep 1999 18:47:52 -0700 (PDT) (envelope-from robinson@netrinsics.com) Received: from netrinsics.com (robinson@[202.106.220.122]) by public.bta.net.cn (8.9.3/8.9.3) with ESMTP id JAA08088 for ; Thu, 16 Sep 1999 09:42:19 +0800 (CST) Received: (from robinson@localhost) by netrinsics.com (8.9.3/8.8.7) id JAA18180; Thu, 16 Sep 1999 09:43:57 +0800 (CST) (envelope-from robinson) Date: Thu, 16 Sep 1999 09:43:57 +0800 (CST) From: Michael Robinson Message-Id: <199909160143.JAA18180@netrinsics.com> To: jeff-ml@mountin.net, robinson@netrinsics.com Subject: Re: Vinum performance testing... Cc: freebsd-stable@freebsd.org In-Reply-To: <3.0.3.32.19990915193638.01de52d0@207.227.119.2> Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG "Jeffrey J. Mountin" writes: >Like anything it will only do what you tell it, so in a way I'm of agreement. My biggest objection to vinum is that it will do what you tell it to, and then complain afterwards, rather than complain about it at the time you try to do it. Two good examples: 1. You can add drives partitions that haven't yet been MAKEDEV'ed into the filesystem. They will be added to the vinum configuration information. Then vinum will give profuse messages about inaccessible devices. 2. You can create a striped plex from unequally-sized subdisks. The plex will be added to the vinum configuration information. Then vinum will give profuse messages complaining that striped subdisks have to be the same size. >>After getting seriously burned (fortunately, during initial system >>configuration), I've sworn off vinum for any sort of critical production >>use. > >When was this? What were you trying do? This was 3.3-RC bits, last week. The specific action was this: I had a 0+1 configuration. One of the mirrored plexes was suffering from problem #2 above, so I had deleted it. However, because the "vinum start" command apparently opens all the partitions and keeps them open, I couldn't change the disklabel on the odd-sized partition. So, I tried to manually start the other plex by "vinum read disk1" followed by "vinum read disk2", instead of "vinum read disk1 disk2". What happened after that was the two subdisks of the striped plex were essentially trashed. All sorts of really cool kernel side effects were visible at that time, such as streams of garbage characters on the console that precluded an orderly shutdown. A couple of hard restarts later, and there wasn't anything left to salvage. I have extensive experience with Veritas Volume Manager under Solaris. In many ways, I think vinum is an excellent replacement. However, it very much seems that it is still in the "try to make it work" stage of development and hasn't yet entered the "try to break it" stage. -Michael Robinson To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message