From owner-freebsd-fs@freebsd.org Thu Oct 29 06:43:01 2015 Return-Path: Delivered-To: freebsd-fs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id B3BE9A201A5 for ; Thu, 29 Oct 2015 06:43:01 +0000 (UTC) (envelope-from ben.rubson@gmail.com) Received: from mailman.ysv.freebsd.org (mailman.ysv.freebsd.org [IPv6:2001:1900:2254:206a::50:5]) by mx1.freebsd.org (Postfix) with ESMTP id 9205314D9 for ; Thu, 29 Oct 2015 06:43:01 +0000 (UTC) (envelope-from ben.rubson@gmail.com) Received: by mailman.ysv.freebsd.org (Postfix) id 9109DA201A4; Thu, 29 Oct 2015 06:43:01 +0000 (UTC) Delivered-To: fs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 77948A201A3 for ; Thu, 29 Oct 2015 06:43:01 +0000 (UTC) (envelope-from ben.rubson@gmail.com) Received: from mail-wm0-x229.google.com (mail-wm0-x229.google.com [IPv6:2a00:1450:400c:c09::229]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 1068714D6 for ; Thu, 29 Oct 2015 06:43:01 +0000 (UTC) (envelope-from ben.rubson@gmail.com) Received: by wmff134 with SMTP id f134so18419022wmf.1 for ; Wed, 28 Oct 2015 23:42:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=content-type:mime-version:subject:from:in-reply-to:date :content-transfer-encoding:message-id:references:to; bh=ICmmBL1qQWwhPHOXAOA/QM0hjWM6hHcHcwWYN8gobkE=; b=KV+1FZfykAb1ERgIPntARuIK34DNiS3lJu11x9mmc8PAWFM331dVUro4JKh1EouTbq KYzH2/r6raofbn8Xxw+EEIPSX+Y5pqSlfYCSKMHWjMzwl14JvS/l8kSpI9eeH5ne1F36 9DDPntejL9fi1HfdVKjaRRajRnDPbI/y80qI0x5Wv2hYwFCbu0F1qkWK/SzrX2cIAMth UTFejlGfdZH0AhsG1Oa2XgkDIv9Ssnk3WFlFKtmyyGBs73T33h1Mrpqj1pxlhjRoUjGd EgyYvbf4PsI6rLAMAwr3HFhZpTDTT0t8bXROK/Ld82cqrMc5mHH/ki6O8I0Ff4iNDBV9 2iew== X-Received: by 10.28.138.140 with SMTP id m134mr1561717wmd.74.1446100979119; Wed, 28 Oct 2015 23:42:59 -0700 (PDT) Received: from [192.168.0.1] (cag06-2-82-237-68-117.fbx.proxad.net. [82.237.68.117]) by smtp.gmail.com with ESMTPSA id om1sm141287wjc.2.2015.10.28.23.42.58 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 28 Oct 2015 23:42:58 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2104\)) Subject: Re: iSCSI/ZFS strangeness From: Ben RUBSON In-Reply-To: Date: Thu, 29 Oct 2015 07:42:57 +0100 Content-Transfer-Encoding: quoted-printable Message-Id: References: <20151029015721.GA95057@mail.michaelwlucas.com> To: fs@freebsd.org X-Mailer: Apple Mail (2.2104) X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 29 Oct 2015 06:43:01 -0000 > Le 29 oct. 2015 =C3=A0 03:26, Philip Murray a = =C3=A9crit : >=20 >=20 >> On 29/10/2015, at 2:57 PM, Michael W. Lucas = wrote: >>=20 >> Hi, >>=20 >> I'm experimenting with iSCSI HA with FreeBSD 10.2 amd64. I know = people >> do this sort of thing, but I can't figure out what I'm missing. (Most >> of the tutorials cover HAST instead). I suspect the real problem is >> "Lucas doesn't know the right search terms." >>=20 >> The goal is to make an iSCSI-based ZFS pool that's available to two >> separate hosts, and remains available even if one of the iSCSI = servers >> fails. Instead, the pool hangs when either of the iSCSI servers goes >> down. >=20 > I=E2=80=99m no expert and have never used iSCSI and FreeBSD before, = but I think you might=20 > want to look at the kern.iscsi.fail_on_disconnection sysctl. >=20 > man 4 iscsi >=20 > That means the devices will fail instead of hang, and ZFS might decide = to mark those=20 > devices as faulted instead of waiting for them to respond. Hi, Yes, kern.iscsi.fail_on_disconnection=3D1 in sysctl.conf will do the = trick. In addition, you can tune the following to minimize the impact / freeze = when iSCSI fails : kern.iscsi.ping_timeout=3D10 kern.iscsi.iscsid_timeout=3D10 kern.iscsi.login_timeout=3D10 In addition, in ctl.conf, perhaps you should use one target instruction = per disk. I began with all my disks/luns into a unique target configuration, but = when a disk fails and you replace it, you need to refresh the iSCSI = configuration using iscsictl -M. At this moment you will loose the = connection to all disks, leading into many ZFS devices failed... So I think a target per disks is better, then you only refresh the dead = target : iscsictl -M -i And last thing, thank you very much for your quality books, a must-have = :) Best regards, Ben=