From owner-freebsd-stable@FreeBSD.ORG Thu Apr 17 18:25:06 2008 Return-Path: Delivered-To: stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A14B7106567C for ; Thu, 17 Apr 2008 18:25:06 +0000 (UTC) (envelope-from petefrench@ticketswitch.com) Received: from angel.ticketswitch.com (angel.ticketswitch.com [IPv6:2002:57e0:1d4e::1]) by mx1.freebsd.org (Postfix) with ESMTP id 63B5A8FC40 for ; Thu, 17 Apr 2008 18:25:06 +0000 (UTC) (envelope-from petefrench@ticketswitch.com) Received: from [10.50.50.2] (helo=smaug.rattatosk) by angel.ticketswitch.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.69 (FreeBSD)) (envelope-from ) id 1JmYn9-000CKd-UO; Thu, 17 Apr 2008 19:25:03 +0100 Received: from dilbert.rattatosk ([10.50.50.6] helo=dilbert.ticketswitch.com) by smaug.rattatosk with esmtp (Exim 4.69 (FreeBSD)) (envelope-from ) id 1JmYn9-0009kn-Ru; Thu, 17 Apr 2008 19:25:03 +0100 Received: from petefrench by dilbert.ticketswitch.com with local (Exim 4.69 (FreeBSD)) (envelope-from ) id 1JmYn9-000Fe7-R4; Thu, 17 Apr 2008 19:25:03 +0100 To: zbeeble@gmail.com In-Reply-To: <5f67a8c40804171109o264ad120wa442f21be8a4bb33@mail.gmail.com> Message-Id: From: Pete French Date: Thu, 17 Apr 2008 19:25:03 +0100 Cc: stable@freebsd.org Subject: Re: Dreadful gmirror performance, though each half works fine X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 17 Apr 2008 18:25:06 -0000 > I have experimented with this rather extensively and have operationally > decided not to use ggated in combination with gmirror --- it doesn't appear > to work as well as one might expect. Ah, thats unmfortunate :-( I oroginally started off using the iscsi initiator and target, which did work O.K., but when actually ran live ended up locking up after several hours,a nd then panicing the kernel. So not ideal - but when it was working it was fine. ggated seems the opposite - doesnt crash, but performance is not suitable for any kind of real use. > I'm somewhat vaguely wondering if zfs with one local and one ggated disk > will work well. I tried ZFS for a while myself, and it works O.K., but has a tendency to panic if it wants memory which it can't get. Despite the many different guides available, I never managed to get it to the point where I would be happy to use it on a production system without worrying about it suddenly becomming memory hungry and dieing. Thanks for the inout though - I am doing some more experimentation with ggate (basically raing some buffers as per a thread I found) and seeing if that helps. BTW, I think ggate is the problem and not gmirror here - gmirror on top of iscsi works fine as I said. -pete.