From owner-soc-status@freebsd.org Tue Jun 30 13:56:13 2015 Return-Path: Delivered-To: soc-status@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 BA97898E1A1 for ; Tue, 30 Jun 2015 13:56:13 +0000 (UTC) (envelope-from prasadjoshi.linux@gmail.com) Received: from mail-vn0-x22c.google.com (mail-vn0-x22c.google.com [IPv6:2607:f8b0:400c:c0f::22c]) (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 771331584 for ; Tue, 30 Jun 2015 13:56:13 +0000 (UTC) (envelope-from prasadjoshi.linux@gmail.com) Received: by vnbg129 with SMTP id g129so1649897vnb.3 for ; Tue, 30 Jun 2015 06:56:12 -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=bqZ80Yuikv8cQ4NVaGs6Bm2HL2DcnZWCqEklkkA5ZGU=; b=HV7gYUgcE4kH9uXX56NA6rTVAFFVqFz7HZ5f9HhrYozbRrFHFOdHKoLE9SINOV8wnu eB++i6bTmc1P9sY9rIN6iUC61wmeqrKvkL+1z9iKahP+GIpz/TdJ7CuaymT5F1THrmqG rgyFMazfFPIv9BwcQYBnv/NIMEa1EU9TALf4tMgXMAuIb2FoqzxIx8QjYlAOSpUGBYOF BSG0LtiAh6Xl0wp0JM9ILvNpmhL3BFymwYbL6CeTj75RuupRGUmTRqWBjLRp+uZgtbbH 8pEeHkKSX4RtyG6RNOYhzVLuB5Rx+tcxCXjt/vlQVRiareuMbwQd4v9RtEB40U6RcLtb +Osg== MIME-Version: 1.0 X-Received: by 10.52.189.75 with SMTP id gg11mr20048616vdc.27.1435672572466; Tue, 30 Jun 2015 06:56:12 -0700 (PDT) Received: by 10.31.190.76 with HTTP; Tue, 30 Jun 2015 06:56:12 -0700 (PDT) In-Reply-To: References: Date: Tue, 30 Jun 2015 19:26:12 +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-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: Tue, 30 Jun 2015 13:56:13 -0000 Week 5 Update - I did not work on GSoC for 3 days in this week. Had to attend full day sessions in the University. - Last week I was faced with a problem with booting alternate (non-active) BE. Plan in this week was to locate the problem. It seems like, during bootup zfsloader needs to initialize libzfs library. The libzfs library initialization fails because '/dev/zfs' cannot be opened. I verified the zfs kernel modules, which create the device are loaded. I think, and as suggested by mentor, I will have to set vfs.root.mountfrom environment variable during bootup. Thanks and Regards, Prasad On Mon, Jun 22, 2015 at 11:42 PM, Prasad Joshi wrote: > 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