From owner-freebsd-fs@FreeBSD.ORG Mon Feb 6 12:37:30 2012 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 7F993106564A for ; Mon, 6 Feb 2012 12:37:30 +0000 (UTC) (envelope-from gkontos.mail@gmail.com) Received: from mail-iy0-f182.google.com (mail-iy0-f182.google.com [209.85.210.182]) by mx1.freebsd.org (Postfix) with ESMTP id 4CAAD8FC12 for ; Mon, 6 Feb 2012 12:37:30 +0000 (UTC) Received: by iaeo4 with SMTP id o4so12771215iae.13 for ; Mon, 06 Feb 2012 04:37:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=9Jy8aAr99lnsT+MxIFkN/yw23Bj1g1p3siVH27RMi6A=; b=s0DN4r3KgppUseeSEcvBdr0xLNJOx7oItaC6gOFsdReIlUaPhmxkHRW/aBrPkxZxXg 5nzxLYVXZjP11qbwcutxEwE0QqftORX9z36ICLA6pKBGiDHFWbGNXPsWwI7Frf8Cq2cY xnHhTVYBfE73JxEQv+VR9vQI+KZXNhHgpirE8= MIME-Version: 1.0 Received: by 10.42.180.9 with SMTP id bs9mr16619648icb.0.1328531849444; Mon, 06 Feb 2012 04:37:29 -0800 (PST) Received: by 10.231.231.17 with HTTP; Mon, 6 Feb 2012 04:37:29 -0800 (PST) In-Reply-To: <4F2FBEDE.5020403@digsys.bg> References: <4F2FBCD2.6000603@my.gd> <4F2FBEDE.5020403@digsys.bg> Date: Mon, 6 Feb 2012 14:37:29 +0200 Message-ID: From: George Kontostanos To: Daniel Kalchev Content-Type: text/plain; charset=ISO-8859-1 Cc: freebsd-fs@freebsd.org Subject: Re: HAST considarations X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 06 Feb 2012 12:37:30 -0000 On Mon, Feb 6, 2012 at 1:51 PM, Daniel Kalchev wrote: > > > On 06.02.12 13:43, Damien Fleuriot wrote: >> >> This issue is due to a bug in OpenBSD 3.8's implementation of CARP. >> >> It triggers if you have net.inet.carp.preempt=1 on the node. >> >> If the sysctl is set, the interface assumes MASTERship immediately upon >> being brought up, then yields in the presence of a better master. > > > I know about this patch, but on my systems > > net.inet.carp.preempt=0 > > I was running 8-stable, now 9-stable on these servers and observe the same > behavior. > > George Kontostanos: > > My setup has 1G interfaces for the CARP/Internet and 10G interfaces for the > backend/HAST. I am doing hast over the 10G interfaces. For a system with > part of 10k SAS drives, and ZFS mirror (each element of the mirror is an > HAST provider), running bonnie++ I see about 100MB/sec flow to the secondary > HAST and that about saturates the disks as well (50-60MB/sec.. should have > been better) > I had earlier experiment with 4 drives in each system and that replicated at > up to 230 MB/sec. > > Daniel I wonder how that numbers would look on striped raidz1 with 10 disks with separate mirrored cache devices. Another question that comes to my mind right now is if the failover scripts should bring up/down the required services for data sharing. That is given the fact that the pool is not mounted until their role is primary, samba for example would complain about it. Also, how about backup strategies? My feeling is that for true HA the only option would be to have a network backup solution that would take over from the currently active node. Of course this requires the failover scripts to start /stop this service as well. Regards -- George Kontostanos Aicom telecoms ltd http://www.aisecure.net