From owner-freebsd-hackers@freebsd.org Mon Dec 7 03:42:58 2020 Return-Path: Delivered-To: freebsd-hackers@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 5BE994756E0 for ; Mon, 7 Dec 2020 03:42:58 +0000 (UTC) (envelope-from ekraju@gmail.com) Received: from mail-yb1-xb34.google.com (mail-yb1-xb34.google.com [IPv6:2607:f8b0:4864:20::b34]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4Cq8KF0Vkkz3nGF for ; Mon, 7 Dec 2020 03:42:56 +0000 (UTC) (envelope-from ekraju@gmail.com) Received: by mail-yb1-xb34.google.com with SMTP id k78so2824062ybf.12 for ; Sun, 06 Dec 2020 19:42:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=5yA7+8CY8xecT3fZ8aRcUgFViLLPcH2iIkBSTBaPSfA=; b=G2zMX3aHKys0fZzzQ8M4YI1gJ62yFgdZK0z5aAX0fvW4N5pEb4xoaAKDMGrcsjvRez cDnxPN0lIALS4zmAfOegue30YVfYZjN6QiKsHufF3at2EOx5IXTOL0lTJ0RMK9o+ITX7 1hokt1rQiUMJX9JgPFgpaEsdpxWMiiNHXhEbbEzfjQm/nUbX8ifB3YxQrbYvbmZ+0D6L TCHmJT9y9jv9GT3m6xdQrMEhVdpVBTrmOmBOUJtBO2bb87052tksKcwmMG67wb7k7Q1x txRcPXHDlsfIOtIePcl8fMisbh0EXxLFoFiNaZxRk1/vvTG+U/DiQ6DY0lidN9ZXUS4Z TMhA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=5yA7+8CY8xecT3fZ8aRcUgFViLLPcH2iIkBSTBaPSfA=; b=OcNSory94cIP11utDtJVcOytWlADBAxKd12P+DaVaBFcvUDWNP6X1yzkajieUEdJV5 7F6kvvHeMmQ/9p7M2K6DRhCipsOHM7cX6YPcqO3o7ZwxHko7joj9BJDvzJW67UEvAV3W 9/m91OJP+gkX0L4vM90hAgmftZbg0ThyToRDMiEL+2Ip+8tG8cUz89mUOcVn6W8Rcabg UhhAm7prqvQ6xqGUu3HyAskRrT+jGg4xdB+UOJu9XzKPHayWm4+nuWSlvwq1I6uWa7Bn MsyKyQHHfl4+WIITy63f1pCFKhJO4Fnbn13tV56Zw4JDT2ZrN4fdnXnSJiUxqpcxGivm ocqw== X-Gm-Message-State: AOAM532EfTUYYOHgB5WfdeKnZIEVDlWHiXfSju+lrZw1XN+S8iWYJW5K DlWJW/Do9IazjZsR61lQiasV6l474ZpExQeTWiJY4Tttq8k= X-Google-Smtp-Source: ABdhPJxxho+ZFCZP8j8+5a1jnJqgAkgO1AbfrHHZXIuvVFBGpl5g+YXH8kmbLzOTRchvvGMaNOL8mhQ0t1mLtiWybxg= X-Received: by 2002:a25:c052:: with SMTP id c79mr7447534ybf.287.1607312576018; Sun, 06 Dec 2020 19:42:56 -0800 (PST) MIME-Version: 1.0 References: <10a5e607-a852-716a-9872-984e7247996e@yuripv.dev> In-Reply-To: From: Krishnamraju Eraparaju Date: Mon, 7 Dec 2020 09:14:47 +0530 Message-ID: Subject: Re: when to use "/dev/nvme0ns1" To: Warner Losh Cc: Yuri Pankov , FreeBSD Hackers X-Rspamd-Queue-Id: 4Cq8KF0Vkkz3nGF X-Spamd-Bar: --- Authentication-Results: mx1.freebsd.org; dkim=pass header.d=gmail.com header.s=20161025 header.b=G2zMX3aH; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (mx1.freebsd.org: domain of ekraju@gmail.com designates 2607:f8b0:4864:20::b34 as permitted sender) smtp.mailfrom=ekraju@gmail.com X-Spamd-Result: default: False [-4.00 / 15.00]; FREEMAIL_FROM(0.00)[gmail.com]; R_SPF_ALLOW(-0.20)[+ip6:2607:f8b0:4000::/36]; TO_DN_ALL(0.00)[]; DKIM_TRACE(0.00)[gmail.com:+]; DMARC_POLICY_ALLOW(-0.50)[gmail.com,none]; NEURAL_HAM_SHORT(-1.00)[-0.999]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+,1:+,2:~]; RBL_DBL_DONT_QUERY_IPS(0.00)[2607:f8b0:4864:20::b34:from]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:2607:f8b0::/32, country:US]; DWL_DNSWL_NONE(0.00)[gmail.com:dkim]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; R_DKIM_ALLOW(-0.20)[gmail.com:s=20161025]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; NEURAL_HAM_LONG(-1.00)[-1.000]; MIME_GOOD(-0.10)[multipart/alternative,text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-hackers@freebsd.org]; SPAMHAUS_ZRD(0.00)[2607:f8b0:4864:20::b34:from:127.0.2.255]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RCVD_IN_DNSWL_NONE(0.00)[2607:f8b0:4864:20::b34:from]; RCVD_COUNT_TWO(0.00)[2]; RCVD_TLS_ALL(0.00)[]; MAILMAN_DEST(0.00)[freebsd-hackers] Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.34 X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 07 Dec 2020 03:42:58 -0000 Thank you Warner Losh & Yuri Pankov. Can I use nvmeXnsY for IO? Looks like fio shows better performance with nvmeXnsY, then nvd/nda devices= . Thanks, ekraju. On Sun, Dec 6, 2020 at 11:13 AM Warner Losh wrote: > > > On Sat, Dec 5, 2020 at 10:36 PM Yuri Pankov wrote: > >> Krishnamraju Eraparaju wrote: >> > Hi All, >> > >> > >> > I see there are two ways of accessing NVMe disk: >> > 1)GEOM based: /dev/nvd0 or /dev/nda0 >> > 2)/dev/nvme0ns1 >> > >> > When should one use " /dev/nvme0ns1"? >> >> See nvmecontrol(8) for the commands that operate on namespace ids. And >> while you could still use nvd/nda devices for those, specifying the >> namespace explicitly could be helpful. >> >> An excerpt from man page: >> >> DEVICE NAMES >> Where =E2=9F=A8namespace-id=E2=9F=A9 is required, you can use eith= er the nvmeXnsY >> device, or the disk device such as ndaZ or nvdZ. The leading /dev= / >> is omitted. >> > > Yes. nvd* and nda* are block devices. nvme0ns1 is for administrative > things when you may or may not have an nda/nvd device hanging around, or > you want to deal with a specific thing and don't know the mapping to the > nda/nvd device. > > Warner >