From owner-freebsd-fs@FreeBSD.ORG Mon Feb 6 11:16:46 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 E82161065680 for ; Mon, 6 Feb 2012 11:16:46 +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 B8E4C8FC1C for ; Mon, 6 Feb 2012 11:16:46 +0000 (UTC) Received: by iaeo4 with SMTP id o4so12639792iae.13 for ; Mon, 06 Feb 2012 03:16:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:date:message-id:subject:from:to:content-type; bh=qQcihKU/odTuSlPUrugHgKsqbNjRaZIEk3diAaF6KsM=; b=YrBRJGl37EIdvMIMmOI7Bx9V2xPN3OVii/R/YV23hHUJ63VUIh0MRi2Uzd7nD+qaYW OeESrJm1+unYchrGVFHQhL66PWpC8Un2h4/OBDfygoX35RhZEjQp6W/Hu1EIbJeXCEjy 6f/Qou/ZqGVItpHK4iP7ATEZlYIhdhE/eLq2w= MIME-Version: 1.0 Received: by 10.50.153.133 with SMTP id vg5mr9609554igb.8.1328525689382; Mon, 06 Feb 2012 02:54:49 -0800 (PST) Received: by 10.231.231.17 with HTTP; Mon, 6 Feb 2012 02:54:49 -0800 (PST) Date: Mon, 6 Feb 2012 12:54:49 +0200 Message-ID: From: George Kontostanos To: freebsd-fs@freebsd.org Content-Type: text/plain; charset=ISO-8859-1 Subject: 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 11:16:47 -0000 Greetings list, I have been experimenting with HAST on a raidz ZFS pool and I have stumbled upon some issues. So, any suggestions are highly appreciated :) My testing environment is consisted of a Linux KVM machine with an Intel Core2Duo and 4G RAM with 2 SATA drives striped (for performance) since I don't have the metal to experiment. When someone is considering to use a HA solution for storage then I am quite sure that their set up would include redundant switches and NICs. For best performance the HAST synchronization should be independent from the CARP interfaces, possibly consisting with more than 1 NIC with lag. At least that's what I think. The first problem appeared when trying to setup the resources. It seems that the resource name is tight up with the machines hostname. My hast.conf looks like this: resource disk1 { on hast1 { local /dev/da0 remote hast2 } on hast2 { local /dev/da0 remote hast1 } } resource disk2 { on hast1 { local /dev/da1 remote hast2 } on hast2 { local /dev/da1 remote hast1 } } However, the hostnames are storage1 and storage2 with storage being the shared CARP IP. Both hast1 & hast2 resolve in /etc/hosts and are connected to a different private vlan but when trying to create the first resource the system complained that only hast1 is an acceptable resource name. After changing both machines hostnames I was able to create the resources and a zpool mirror consisted upon /dev/hast/disk1 & /dev/hast/disk2 Manual failover also worked by exporting the pool from the master, switching roles and then importing the pool on the slave. Yet, looking at the example scripts I realized that there is a lot of work to be done since automatic failover is based upon the CARP device and is limited to one resource. I replicated the resources at the script level in order to switch roles for all the devices. Still it looks very basic and crapy. Also, I added the NIC witch is being used for HAST replication to the /etc/devd.conf besides CARP I see this being at an early stage but I was wondering if anyone has to share some success (or not) stories. Also, does anyone else share my point regarding separating CARP and HAST replication? If yes I would be very interesting to know how this was done. Regards -- George Kontostanos Aicom telecoms ltd http://www.aisecure.net