From owner-freebsd-questions@freebsd.org Thu Jan 17 05:35:15 2019 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id F41141482C26 for ; Thu, 17 Jan 2019 05:35:14 +0000 (UTC) (envelope-from 4250.10.freebsd-questions=freebsd.org@email-od.com) Received: from s1-b0c6.socketlabs.email-od.com (s1-b0c6.socketlabs.email-od.com [142.0.176.198]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id C712973684 for ; Thu, 17 Jan 2019 05:35:13 +0000 (UTC) (envelope-from 4250.10.freebsd-questions=freebsd.org@email-od.com) DKIM-Signature: v=1; a=rsa-sha256; d=email-od.com;i=@email-od.com;s=dkim; c=relaxed/relaxed; q=dns/txt; t=1547703314; x=1550295314; h=content-transfer-encoding:content-type:mime-version:references:in-reply-to:message-id:subject:cc:to:from:date:x-thread-info; bh=BAsucpMpXE2RJKNX4+NM9T4BleRmOSK8DVv2nujT3so=; b=l9znNru/MgxyKI0MixuhBpHkONv/HzOSkWufZlIzwHB65QY+G9zc6cbgRU7C5xHO4DdxjtI1NBOmnTGP0zb86CAAhSGdYcUu24U+ZsOTjUaA1i7fAndRsanv/g0WBOy8vCvvwhFzlRQ3FYnnksHBSM/O0FUSPmDvsm6cJ5z6ZXI= X-Thread-Info: NDI1MC4xMi4xYTMwMDAwMDBhMjZkMmEuZnJlZWJzZC1xdWVzdGlvbnM9ZnJlZWJzZC5vcmc= Received: from r2.sg.in.socketlabs.com (r2.sg.in.socketlabs.com [142.0.179.12]) by mxsg2.email-od.com with ESMTP(version=Tls12 cipher=Aes256 bits=256); Thu, 17 Jan 2019 00:35:09 -0500 Received: from smtp.lan.sohara.org (EMTPY [89.127.62.20]) by r2.sg.in.socketlabs.com with ESMTP(version=Tls12 cipher=Aes256 bits=256); Thu, 17 Jan 2019 00:35:08 -0500 Received: from [192.168.63.1] (helo=steve.lan.sohara.org) by smtp.lan.sohara.org with smtp (Exim 4.91 (FreeBSD)) (envelope-from ) id 1gk0KX-000A3T-RR; Thu, 17 Jan 2019 05:35:05 +0000 Date: Thu, 17 Jan 2019 05:35:05 +0000 From: Steve O'Hara-Smith To: byrnejb@harte-lyne.ca Cc: freebsd-questions@freebsd.org Subject: Re: Memory usage appears a bit high Message-Id: <20190117053505.cd2322c53eb451bfafb1f039@sohara.org> In-Reply-To: <8f1f1f6c5532a9b076d878ff98a9044c.squirrel@webmail.harte-lyne.ca> References: <35c451bc1733004b7d868f60da68c639.squirrel@webmail.harte-lyne.ca> <20190116173621.9d90157c1adf526298763415@sohara.org> <0c45ab67b1480d39dd87059495f6a27c.squirrel@webmail.harte-lyne.ca> <20190116181146.375e2358d2091380c74a8291@sohara.org> <8f1f1f6c5532a9b076d878ff98a9044c.squirrel@webmail.harte-lyne.ca> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.32; amd64-portbld-freebsd12.0) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: C712973684 X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org; dkim=pass header.d=email-od.com header.s=dkim header.b=l9znNru/; spf=pass (mx1.freebsd.org: domain of 4250.10.freebsd-questions=freebsd.org@email-od.com designates 142.0.176.198 as permitted sender) smtp.mailfrom=4250.10.freebsd-questions=freebsd.org@email-od.com X-Spamd-Result: default: False [-2.93 / 15.00]; R_SPF_ALLOW(-0.20)[+ip4:142.0.176.0/20]; MV_CASE(0.50)[]; TO_DN_NONE(0.00)[]; RCVD_COUNT_THREE(0.00)[4]; DKIM_TRACE(0.00)[email-od.com:+]; RCPT_COUNT_TWO(0.00)[2]; MX_GOOD(-0.01)[cached: mxbh.socketlabs.com]; FORGED_SENDER(0.00)[steve@sohara.org,4250.10.freebsd-questions=freebsd.org@email-od.com]; IP_SCORE(-0.23)[ip: (-0.58), ipnet: 142.0.176.0/22(-0.28), asn: 7381(-0.23), country: US(-0.08)]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:7381, ipnet:142.0.176.0/22, country:US]; RCVD_TLS_LAST(0.00)[]; FROM_NEQ_ENVFROM(0.00)[steve@sohara.org,4250.10.freebsd-questions=freebsd.org@email-od.com]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-0.99)[-0.990,0]; R_DKIM_ALLOW(-0.20)[email-od.com:s=dkim]; MID_RHS_MATCH_FROM(0.00)[]; FROM_HAS_DN(0.00)[]; NEURAL_HAM_SHORT(-0.70)[-0.699,0]; NEURAL_HAM_LONG(-1.00)[-0.996,0]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[sohara.org]; FORGED_SENDER_VERP_SRS(0.00)[]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RCVD_IN_DNSWL_NONE(0.00)[198.176.0.142.list.dnswl.org : 127.0.15.0]; ENVFROM_VERP(0.00)[] X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 17 Jan 2019 05:35:15 -0000 On Wed, 16 Jan 2019 15:45:08 -0500 "James B. Byrne" wrote: > As I have never meddled with the sysctl settings on this bhyve host I > infer that this setting in sysctl is calculated based on the total > memory allocated when the vm is created: > > vfs.zfs.arc_max: 3043799040 Which is probably fine if the server isn't doing anything else that demands much memory. > How much should be committed to arc in a 4GB system? What are the > benefits / costs of more or less ram allocated to arc? The more RAM in the ARC the better the caching and therefore (with a cache friendly workload) the faster the filesystem and the lower the rate of wear on the drives. The downside - the ARC is wired so you need to assess how much RAM the server needs for other tasks and throttle the ARC to suit. -- Steve O'Hara-Smith | Directable Mirror Arrays C:\>WIN | A better way to focus the sun The computer obeys and wins. | licences available see You lose and Bill collects. | http://www.sohara.org/