From owner-freebsd-questions@freebsd.org Fri Oct 16 18:36:23 2020 Return-Path: Delivered-To: freebsd-questions@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 00C1443CDBF for ; Fri, 16 Oct 2020 18:36:22 +0000 (UTC) (envelope-from kudzu@tenebras.com) Received: from mail-lj1-x22d.google.com (mail-lj1-x22d.google.com [IPv6:2a00:1450:4864:20::22d]) (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 4CCZc60VH4z43DB for ; Fri, 16 Oct 2020 18:36:21 +0000 (UTC) (envelope-from kudzu@tenebras.com) Received: by mail-lj1-x22d.google.com with SMTP id p15so3538865ljj.8 for ; Fri, 16 Oct 2020 11:36:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tenebras-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=eoibjFHXIxjW4h1eN4aDJBz6n1mrfxqMa89paVrP3zc=; b=qTtu6E13mXoy4qfxIajJaHzagD74peVS4As0A6De9BNRcHwVKoeyuZbZnlUx2tWu+M 0HJ8TkGdvxGXbZKwd+t8cp1ddq7lRCXuTzXZuKjjS6T0lTMNMXOM6nRylr/eRBFNYAfY ck10qmDjP3ODGJyBl1pUjz305SKYejvzeP1iMH/MsjYQeXc3hJWXHzxE/t6/AlyuUMYJ RaVxGnT6W1mF48tfqohEEs7yIeUB8QZbNYYTdkW70mI3IxU2pxSX7hStc90/7lcpe9dv JvmDna2aeMWM6pn6NL1i7LyFHJ/Ah+vGD3PIB33HS6C7W0lpWJU/k1W7zyUSnTXXSGV6 bKjQ== 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; bh=eoibjFHXIxjW4h1eN4aDJBz6n1mrfxqMa89paVrP3zc=; b=egmB95RF1J35o2ZBQev/R8LyMTFXqEDibFFj9eJaGe88WaKoTbbb77oHwQ0KErVMj5 IgIPKq1iTbvz9Ll8FqYZtfkK/tey6qJ+gYwop4YGMfKxAWdHyHLW2eYNYTIRbQsgoF05 F57LMn69aZbzQADasOOOT8mEImZyJ6cXmw30Y+QP/LjE4eqql4/8Jf74vOQs3mRyKbML J07tV750iPJ8nm+rG0SLW0/WsYT8ZujwLifCjFVOz3aFchQD0kmYIto70nwLh6Xh6D5T wz/fpWzyE1+5Th51DYW7UjfQPV14++OZyJeOu6gOFs55XmuSjXKuYvQM7tscJjmrjpqL cleA== X-Gm-Message-State: AOAM532wxVZHdWZ9HasnpIT/wdeVCJA3njEWLqCr5VZdNIMjhkrzucjX y+RTXY6jo1pNWeuar6EoTF61XhlOzDWqRMClOsAeOmF0DI7xAcXA X-Google-Smtp-Source: ABdhPJz32OT4GCW8wryg3JmnBLMBsoCkXQQtkjdz/chz76wfFfzLHqGNuJ1BYLbAIwkwxVpnJ1vn2hR8EZV2qV3dl2Y= X-Received: by 2002:a2e:9c84:: with SMTP id x4mr2105882lji.326.1602873377885; Fri, 16 Oct 2020 11:36:17 -0700 (PDT) MIME-Version: 1.0 References: <5f885b772d622_95aa2adab2b9c5b41576495c3@sirportly-app-02.mail> In-Reply-To: <5f885b772d622_95aa2adab2b9c5b41576495c3@sirportly-app-02.mail> From: Michael Sierchio Date: Fri, 16 Oct 2020 11:35:42 -0700 Message-ID: Subject: Re: FreeBSD using swap even though there's a lot of free memory To: FreeBSD Questions X-Rspamd-Queue-Id: 4CCZc60VH4z43DB X-Spamd-Bar: - Authentication-Results: mx1.freebsd.org; dkim=pass header.d=tenebras-com.20150623.gappssmtp.com header.s=20150623 header.b=qTtu6E13; dmarc=none; spf=none (mx1.freebsd.org: domain of kudzu@tenebras.com has no SPF policy when checking 2a00:1450:4864:20::22d) smtp.mailfrom=kudzu@tenebras.com X-Spamd-Result: default: False [-1.06 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-0.57)[-0.567]; R_DKIM_ALLOW(-0.20)[tenebras-com.20150623.gappssmtp.com:s=20150623]; FROM_HAS_DN(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; NEURAL_HAM_LONG(-0.64)[-0.644]; MIME_GOOD(-0.10)[multipart/alternative,text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-questions@freebsd.org]; DMARC_NA(0.00)[tenebras.com]; RCPT_COUNT_ONE(0.00)[1]; TO_DN_ALL(0.00)[]; DKIM_TRACE(0.00)[tenebras-com.20150623.gappssmtp.com:+]; RCVD_IN_DNSWL_NONE(0.00)[2a00:1450:4864:20::22d:from]; NEURAL_SPAM_SHORT(0.45)[0.451]; R_SPF_NA(0.00)[no SPF record]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+,1:+,2:~]; ASN(0.00)[asn:15169, ipnet:2a00:1450::/32, country:US]; RCVD_TLS_ALL(0.00)[]; MAILMAN_DEST(0.00)[freebsd-questions]; RCVD_COUNT_TWO(0.00)[2] Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.33 X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 16 Oct 2020 18:36:23 -0000 On Thu, Oct 15, 2020 at 7:24 AM Twingly Customer Support wrote: > Hi, > > We have a server running FreeBSD 12.1-RELEASE-p10. We currently have a > problem where FreeBSD starting to swap when running ZFS scrub, even thoug= h > we have ~70G of free memory. tl;dr =E2=80=93 this is normal, nothing to see, move along. It's not "swapping" =E2=80=93 it's paging pre-emptively. If you're used to= Linux, you might think "swap bad" ;-) There is a lot of history to VM management in BSD. This might be an easy place to start: https://flylib.com/books/en/2.849.1.78/1/ --=20 "Well," Brahm=C4=81 said, "even after ten thousand explanations, a fool is = no wiser, but an intelligent person requires only two thousand five hundred." - The Mah=C4=81bh=C4=81rata