From nobody Sun Jan 14 17:58:13 2024 X-Original-To: freebsd-current@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4TCjgQ6gjyz56mbZ for ; Sun, 14 Jan 2024 17:58:26 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: from mail-lj1-x235.google.com (mail-lj1-x235.google.com [IPv6:2a00:1450:4864:20::235]) (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 1D4" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4TCjgQ61LVz4Yhr for ; Sun, 14 Jan 2024 17:58:26 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Authentication-Results: mx1.freebsd.org; none Received: by mail-lj1-x235.google.com with SMTP id 38308e7fff4ca-2cd0c17e42bso91011121fa.0 for ; Sun, 14 Jan 2024 09:58:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bsdimp-com.20230601.gappssmtp.com; s=20230601; t=1705255105; x=1705859905; darn=freebsd.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=Df+M0vSGv+DqtUQvZzMCiBBwf8K32S2PE2gIKd6IYQU=; b=U5dxMeovUvMglnfgn46z/gSCDTivKkPmU1vkZWRmZ6FL97mKN7FnFrjkvmixg661BP Gr3R1JhvPptbCz6Dx93Hc3JUwa3Iws+BAcpBlmufySczh6PlUEDTpNOknTpzaJ1iOJsE ZrlXy7jpOYetmcedUMByfLa1XeX6idu+opc2AUlppeSZCjtVm/zqgYdV33hhDjwPS9NP zvyIQsJ5JEqMsT5AhwlorbMDCB8+tf5Lh4qrWrbkg69fPeQPkGxtggM9+Xb5oJgiJjIw +JvFJQbCm9xMN2O4+UDf7rhOhdcd5sLS59QOHhzRJ08gDWPO/RMPzv/C5PpzASn1RTSZ 9SJQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1705255105; x=1705859905; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=Df+M0vSGv+DqtUQvZzMCiBBwf8K32S2PE2gIKd6IYQU=; b=YM3Rbo/gbga6IBo6l1zXg1SMFWlAau9G4EPq6zd52KQqMgws0y9pjgNOH1tnyX95o7 rd34eAfmKi7R+DDtxPMpQQOXZrr1d72772p0zBkhi1xE+NfQh7IaFCQ7uYxzF9Y8QsGj l9tXFCbm8i2XmarqaxMMo+hNJq1ugWZlAwyjvMsbDeIlCQkM72vip5St3rX0eYPqMhFz uYZSUdiDfYcfPTuR7j2YalTuU4MQPGmffKGwszovsyiOL/SHSjIRwo09qJnDcAMOp61u QlrFlD5PQ8oJl63UYs2+AkA8NMKGCidg0ymY2HMD4qsiRyWLU9fcs/Dy2xlyYQOmNY4M GcjQ== X-Gm-Message-State: AOJu0YyadeK3prtEOmhm5QBDnEzvL7EYHeOcyQItH9gy0cj41leT0g8D yf2wAvUC5rJtp7Cnxxxe8u/psDO/5JL5NiDPrJHapXIGkZ455Mb9+wWB9stZOBU= X-Google-Smtp-Source: AGHT+IF8E8BUiAY0ygoZfuQ8ebJ52y3y5M2pAH+KdMIAzP/V1AHLesRNn8Dx5PJZ4nPIZniQRBT726keoi035eiSutE= X-Received: by 2002:a19:6756:0:b0:50e:7b10:71ab with SMTP id e22-20020a196756000000b0050e7b1071abmr1744493lfj.95.1705255105206; Sun, 14 Jan 2024 09:58:25 -0800 (PST) List-Id: Discussions about the use of FreeBSD-current List-Archive: https://lists.freebsd.org/archives/freebsd-current List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-current@freebsd.org MIME-Version: 1.0 References: <4014880.cjyAsbXg9l@ravel> In-Reply-To: From: Warner Losh Date: Sun, 14 Jan 2024 10:58:13 -0700 Message-ID: Subject: Re: noatime on ufs2 To: "Lyndon Nerenberg (VE7TFX/VE6BBM)" Cc: Olivier Certner , Rick Macklem , FreeBSD Current Content-Type: multipart/alternative; boundary="000000000000cc2fc6060eeba4fb" X-Rspamd-Queue-Id: 4TCjgQ61LVz4Yhr X-Spamd-Bar: ---- X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; TAGGED_RCPT(0.00)[]; ASN(0.00)[asn:15169, ipnet:2a00:1450::/32, country:US] --000000000000cc2fc6060eeba4fb Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Sun, Jan 14, 2024, 10:24=E2=80=AFAM Lyndon Nerenberg (VE7TFX/VE6BBM) < lyndon@orthanc.ca> wrote: > > > I do not have a strong opinion w.r.t. atime, but I do believe that > > > changing the default would be a POLA violation. > > I'm not prepared to just accept that at face value. > > I can't think of a single instance in at least the last three decades > where I have actually used or needed atime for *anything*. And > over that time period I have been responsible for running hundreds > of UNIX servers. > > I'm really interested in hearing from people who actively use > atime on a regular basis for non-trivial purposes. What are > the modern use cases for atime? > The consensus was we'd fix it in the installer. We can't change ZFS easily, and discovery of the problem, should your assertion be wrong, for UFS means metadata loss that can't be recovered. By pushing to the installer, most installations get most of benefits. And people with special needs see the issue and can make an informed choice. Though in all honesty, I've never been able to measure a speed difference. Nor have I worn out a ssd due to the tiny increase in write amp. Old (<100MB) SD and CF cards included. This includes my armv7 based dns server that I ran for a decade on a 256MB SD card with no special settings and full read/write and lots of logging. So the harm is minimal typically. I'm sure there are cases that it matters more than my experience. And it is good practice to enable noatime. Just that failure to do so typically has only a marginal effect. Warner --lyndon > > --000000000000cc2fc6060eeba4fb Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


On Sun, Jan 14, 2024, 10:24=E2=80=AFAM Lyndon Nerenber= g (VE7TFX/VE6BBM) <lyndon@orthanc.c= a> wrote:
> > I do not= have a strong opinion w.r.t. atime, but I do believe that
> > changing the default would be a POLA violation.

I'm not prepared to just accept that at face value.

I can't think of a single instance in at least the last three decades where I have actually used or needed atime for *anything*.=C2=A0 And
over that time period I have been responsible for running hundreds
of UNIX servers.

I'm really interested in hearing from people who actively use
atime on a regular basis for non-trivial purposes.=C2=A0 What are
the modern use cases for atime?

The consensus was we'd fix it in the ins= taller.

We can't cha= nge ZFS easily, and discovery of the problem, should your assertion be wron= g, for UFS means metadata loss that can't be recovered.

By pushing to the installer, most ins= tallations get most of benefits. And people with special needs see the issu= e and can make an informed choice.

Though in all honesty, I've never been able to measure a spe= ed difference. Nor have I worn out a ssd due to the tiny increase in write = amp. Old (<100MB) SD and CF cards included. This includes my armv7 based= dns server that I ran for a decade on a 256MB SD card with no special sett= ings and full read/write and lots of logging. So the harm is minimal typica= lly. I'm sure there are cases that it matters more than my experience. = And it is good practice to enable noatime. Just that failure to do so typic= ally has only a marginal effect.

Warner

--lyndon

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