From owner-soc-status@FreeBSD.ORG Mon Jun 22 18:12:03 2015 Return-Path: Delivered-To: soc-status@nevdull.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id E8852BEC for ; Mon, 22 Jun 2015 18:12:03 +0000 (UTC) (envelope-from prasadjoshi.linux@gmail.com) Received: from mail-vn0-x22e.google.com (mail-vn0-x22e.google.com [IPv6:2607:f8b0:400c:c0f::22e]) (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 A0143905 for ; Mon, 22 Jun 2015 18:12:03 +0000 (UTC) (envelope-from prasadjoshi.linux@gmail.com) Received: by vnbg1 with SMTP id g1so9307210vnb.12 for ; Mon, 22 Jun 2015 11:12:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=JJMvKi+hA9jN6+O3mHBm5rY9GHYYaq0t06ytODF9cAo=; b=YJabAvZoZis714EJuWuhA3/VrLYKBGVglwaZXgffYlx7vAPNBAEwQ+GwB7ewut90Id oOAWSBGCvpNXpu1hv9d2r/PbSjMBGhMYHhcjb/ID7AtI0incGK3wWUbIBuBmQKBFFaRJ 1TiYkIu/0aVCsQp6pIRyqvqYUmaZOPbjMRtW0wosBce6SNYdAHc5cyNpghaLwqK6mA8Z NJwYd/jyOxbnjpYDOgW3F4Fg+yFHSFrQ5mEWJsYzDO110xdA2XTCHuYqgOQz6Vs15DzI YRUX1jp4bODZFQUFXAs+ah85y2VdpNe2m0AjJXvoF5iMWh3oW9LVVZHg3nxZDIKdFiZe vcog== MIME-Version: 1.0 X-Received: by 10.52.170.237 with SMTP id ap13mr26498100vdc.5.1434996722636; Mon, 22 Jun 2015 11:12:02 -0700 (PDT) Received: by 10.31.190.76 with HTTP; Mon, 22 Jun 2015 11:12:02 -0700 (PDT) Received: by 10.31.190.76 with HTTP; Mon, 22 Jun 2015 11:12:02 -0700 (PDT) In-Reply-To: References: Date: Mon, 22 Jun 2015 23:42:02 +0530 Message-ID: Subject: Re: [gsoc15] dynamically discover bes From: Prasad Joshi To: soc-status@freebsd.org Cc: Xin LI Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.20 X-BeenThere: soc-status@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Summer of Code Status Reports and Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 22 Jun 2015 18:12:04 -0000 Week 4 update - I have been able to discover BEs on console. I could detect active BE. Created list of BEs. Code to sort BEs on object number, name, or timestamp is added. - I am able to boot from nonactive BE to some extent. At the moment, code requires me to enter BE number to boot from. Tasks next week 1. Identify a problem with be bootup. 2. Pass mount point info through env variable to loader. 3. Start with console based menu. Thanks and Regards, Prasad On Jun 15, 2015 7:48 PM, "Prasad Joshi" wrote: > Week 3 status > ========== > After understanding on disk representation of snapshots and clones, I > have been able to find names of the BEs created using beadm command. I > could print the BE names on console. > > The next task would be to convert BE names to object numbers, create > list of BEs. > > Thanks and Regards, > Prasad > > On Tue, Jun 9, 2015 at 6:36 AM, Prasad Joshi > wrote: > > Last week I mostly worked on understanding beadm and gptzfsboot code > > > > beadm create prepares new BE by creating a snapshot and clone of that > > snapshot. beadm activate command sets bootfs property of the POOL. > > bootfs property contains object number of active dataset object. > > During bootup gptzfsboot probes all the disks, creating SPA for any > > valid pool. gptzfsboot assumes the first pool it finds as a primary > > pool, it then reads meta object set, then tries to find object nunber > > of active dataset object either through > > a. bootfs - it would be set if BE was already created > > b. mos->properties_zap->root_dataset->dd_head_dataset_obj (through > > root_datasets bonus buffer) > > Once the object number is obtaind gptzfsboot mounts the dataset. > > > > After mounting, few files are looked up like /boot/config or > > /boot.config for presense of boot command (did not went into details > > of this). Then (if keyboard is not hit), gptzfsboot execs > > /boot/zfsloader. If gptzfsboot is interrupted by keyboard, then it > > displays default BE or POOL it is trying to boot from (using > > zfs_rlookup() to map active dataset object to string BE name). Though > > I haven't checked this but through serial console user would be > > allowed to enter other pool or BE to boot from. > > > > I could not go into details of how gptzfsboot reads /boot/zfsloader from > disk. > > > > Pending Tasks > > ============= > > 1. Understand upon keyboard interruption, how user entered zfs paths > > (format [zfs:pool/filesystem:][/path/to/loader]) are converted in > > object numbers? > > 2. Learn ZFS on disk format in more details so as to identify active > > dataset object numbers of all BEs. Once the object numbers are > > available, I can use zfs_rlookup() function to map object number to > > printable pool name. > > 3. Prepare library for console based menu. > > > > Plan for next week > > ================== > > Pending task 2 above >