From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Williams Subject: Re: [AUTOREBUILD 0/8] Autorebuild monitor patches based on user defined policy Date: Mon, 18 Oct 2010 23:54:06 -0700 Message-ID: <4CBD408E.9030707@intel.com> References: <905EDD02F158D948B186911EB64DB3D171D09950@irsmsx503.ger.corp.intel.com> <20101019114027.37d65a8c@notabene> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20101019114027.37d65a8c@notabene> Sender: linux-raid-owner@vger.kernel.org To: Neil Brown Cc: "Labun, Marcin" , "linux-raid@vger.kernel.org" , "Czarnowska, Anna" , "Hawrylewicz Czarnowski, Przemyslaw" , "Neubauer, Wojciech" , "Ciechanowski, Ed" , "dledford@redhat.com" List-Id: linux-raid.ids On 10/18/2010 5:40 PM, Neil Brown wrote: > On Fri, 1 Oct 2010 13:36:48 +0100 > "Labun, Marcin" wrote: > >> > From f423b226f10cfe3b416c5e0580dde45cd8ca887d Mon Sep 17 00:00:00 2001 >> From: Marcin Labun >> Date: Wed, 29 Sep 2010 06:12:38 +0200 >> Subject: [AUTOREBUILD 0/8] Autorebuild monitor patches based on user defined policy >> >> This is updated series of patches forming autorebuild functionality in mdadm >> monitor based on new policy code. > > Hi Marcin, > thanks for this, and apologies for not replying sooner. > I've had a bit of a look and some of it seems good. > I haven't had a thorough look yet as I am in the middle of doing some fairly > serious refactoring of mdadm (the supertype, and mdinfo structures are going > to be heavily changed and largely merged - some super_switch methods will > disappear (e.g. getinfo_super) and others will appear (load_container)). > Once I have finished that I will review your code more thoroughly and merge > it into the new code base. > > One concern I do have is patch 0002 which removes the spare-group based > spare migration. That functionality needs to stay, though obviously the > implementation can change. I imagine the 'spare-group' information would be > added to each member device as a 'domain' name. > > Also it is best not to remove functionality and then re-add it a different > way, but rather to make sure the functionality works after every change, but > just gets extended at various points. Hi Neil, I made a similar comment on this patch during our internal review. We also talked about the need for superswitch methods that can be used to 1/ determine which devices in a container are spares versus stale disks 2/ what the minimum size a bare disk needs to be to join a container. I'll wait to see if these items will be easier to determine with the new mdinfo/supertype refactoring. Other notes: The --activate-domains option [1] to validate the configuration file and install custom/filtered udev rules for the ports we care about, seemed like a good idea at the time. Now that things are a bit further along do you have a better solution in mind or is this still the approach we want to take? Przemek currently has a patch to filter all block device events through mdadm to query the configuration file for domain events which seems like overkill if not a performance problem for large disk count environments. We also talked about migration, but I'll put those details in a separate thread. Thanks, Dan [1]: http://marc.info/?l=linux-raid&m=127001124615043&w=2