From owner-svn-src-head@freebsd.org Thu May 19 15:54:29 2016 Return-Path: Delivered-To: svn-src-head@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 A2E4FB41B9D; Thu, 19 May 2016 15:54:29 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: from mail-io0-x230.google.com (mail-io0-x230.google.com [IPv6:2607:f8b0:4001:c06::230]) (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 778741301; Thu, 19 May 2016 15:54:29 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: by mail-io0-x230.google.com with SMTP id t40so20413165ioi.0; Thu, 19 May 2016 08:54:29 -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; bh=y/VdJnm9rjTaw7YsxvBI9RjzLJDy6rhSL55X6Mo5R7I=; b=S3JF1H024lccqsPWtdOQkLjJRuNzg+jNHyRElBcMk7bnZ7vEHbw3e1gw94F4rQeVBz Ob4Jr3j6h/rSBMcHDcEcEesx0RpOu+24HeFel0Oqnz8BKnWmsSz0G/28Y1o7+eFV2+4K MGBFF0kXqR4Ecj09tM4y8Y+qM+qXtGj7+s+cM7jbH98gp4GtcKG0e93AXU5m5fKDQkww TNwjbYSg3M3DpFbataf1JZ43JJU3nPJ7GBs5sR3LWyLFP8Is0aJoKKiHsTDmA1YuIXNX ZK4EnYe6v4pT0q7moWD5RW1Gl1jYW6NYw/bzdvVdtoGWyx4iwrAVlgWcEI6O6a1k5vGq IXXw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc; bh=y/VdJnm9rjTaw7YsxvBI9RjzLJDy6rhSL55X6Mo5R7I=; b=dFlvPorayJWuLG5RYduNLEmn0EHz+sb4UZvMFpDj7jXe+48GfCjiRxOiysnxGGlsXs m4WV3RYaknG/vScc38VoWY9mmu0YWvKSO69DZ8IuVbihAIr0Kt/a7Pk+3xxTwIFT0z2b EZPPG5fUBRh7oLTLiW4YhgW3/1j+miIbjpZq4VrIiKdWzXb/NQOtrbzWAiwJnSafUn3U EcqJxQUU6VOEAl3xgeOZzEgJrlB5NpMQYVoAG7qkSVtyGOWlPL1F9RMm6+0qLBixo6wW BfAeREC8hXLvlP6/LSoAztwtBvjiIC6Bydnk0GSBB2dkGqeych8/3gVSKBEBCrTzJFji W44A== X-Gm-Message-State: AOPr4FVRXJE7f2Cd15VF6iNErKQ4uu4vU7NznZhJoxhi5GVVAdWP3M5N1u/AzuH0RRnP3P+miLSr2a6YHwY5Eg== MIME-Version: 1.0 X-Received: by 10.36.83.65 with SMTP id n62mr3322709itb.71.1463673268726; Thu, 19 May 2016 08:54:28 -0700 (PDT) Received: by 10.36.113.3 with HTTP; Thu, 19 May 2016 08:54:28 -0700 (PDT) In-Reply-To: <20160519145033.GA69089@mithlond.kdm.org> References: <201605191408.u4JE8aPL079390@repo.freebsd.org> <573DCE0D.70400@fastmail.net> <20160519145033.GA69089@mithlond.kdm.org> Date: Thu, 19 May 2016 08:54:28 -0700 Message-ID: Subject: Re: svn commit: r300207 - in head: sbin/camcontrol sys/cam/ata sys/cam/scsi sys/dev/ahci sys/geom sys/geom/eli sys/kern sys/sys usr.sbin usr.sbin/diskinfo usr.sbin/zonectl From: Adrian Chadd To: "Kenneth D. Merry" Cc: Bruce Simpson , "src-committers@freebsd.org" , "svn-src-all@freebsd.org" , "svn-src-head@freebsd.org" Content-Type: text/plain; charset=UTF-8 X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 19 May 2016 15:54:29 -0000 On 19 May 2016 at 07:50, Kenneth D. Merry wrote: > On Thu, May 19, 2016 at 15:30:37 +0100, Bruce Simpson wrote: >> Right On Commander! >> >> Now here is hoping the random-write issues with OpenZFS are solved... > > Well, this is of course only the underlying infrastructure for SMR drives. > > As for the random write issues with ZFS (or rather sequential I/O going out > in random order), we (Spectra) are working on that in general. > > The original plan was to do full SMR support for ZFS, but it looks like we > may get good enough write performance with Drive Managed drives by just > making writes from ZFS to drives more sequential rather than going for full > Host Aware and Host Managed support. If that turns out that performance > isn't good enough after all, then we'll have to put in the effort to put > Host Aware support at least into ZFS. > > That's why I said (in the commit message) that I don't know of anyone > working on using the SMR infrastructure for UFS or ZFS. Now that the > plumbing is in place in CAM and GEOM, it is possible at the filesystem > level if someone wants to do the work. Is it possible to use this from userland for now? Ie, probe whatever we need to in order to understand the transaction geometries (ie, the optimal sizes for reading/writing, etc) and then issue IOs that are in line with this? -adrian