From owner-freebsd-questions@freebsd.org Fri Feb 14 18:29:36 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 C876023D680 for ; Fri, 14 Feb 2020 18:29:36 +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-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 48K23M4r06z40jS for ; Fri, 14 Feb 2020 18:29:35 +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=1581704976; x=1584296976; h=content-transfer-encoding:content-type:mime-version:references:in-reply-to:message-id:subject:cc:to:from:date:x-thread-info; bh=6Kpx2T0Tw1XK4D0S6i6u23EeyxTmzFsoLhMFRQVjMYY=; b=E9lGPmmoo1ZEIO2JVIoSSNJ1VdEH/TFh4pzu1u1DrkeNKbHrzbLHia+7F8Rp072RjZV0PjNM9uqsFK2J5aYgpdBYey8NIFOhphSFDgMvV7J0y3qronwtAHt929U0qBeGfOvNgXecG93vv87zzPa8dNXRgHLezkh+bWbchp8CakU= X-Thread-Info: NDI1MC4xMi43NDAwMDAwMDM2OTA3Zi5mcmVlYnNkLXF1ZXN0aW9ucz1mcmVlYnNkLm9yZw== Received: from r3.us-east-1.aws.in.socketlabs.com (r3.us-east-1.aws.in.socketlabs.com [142.0.191.3]) by mxsg2.email-od.com with ESMTP(version=Tls12 cipher=Aes256 bits=256); Fri, 14 Feb 2020 13:29:32 -0500 Received: from smtp.lan.sohara.org (EMTPY [185.202.17.215]) by r3.us-east-1.aws.in.socketlabs.com with ESMTP(version=Tls12 cipher=Aes256 bits=256); Fri, 14 Feb 2020 13:29:31 -0500 Received: from [192.168.63.1] (helo=steve.lan.sohara.org) by smtp.lan.sohara.org with smtp (Exim 4.92.3 (FreeBSD)) (envelope-from ) id 1j2fiU-000AzS-HD; Fri, 14 Feb 2020 18:29:30 +0000 Date: Fri, 14 Feb 2020 18:29:30 +0000 From: Steve O'Hara-Smith To: Robert Huff Cc: tech-lists , freebsd-questions@freebsd.org Subject: Re: some questions about disk partitioning and filesystems and booting Message-Id: <20200214182930.df325195e2a378a3b6f50573@sohara.org> In-Reply-To: <24134.39022.519866.759080@jerusalem.litteratus.org> References: <20200213150229.GC14144@bastion.zyxst.net> <20200213155256.GD14144@bastion.zyxst.net> <1090523a-377c-9412-5db1-38e825e35956@mm.st> <20200214121003.GB39057@bastion.zyxst.net> <24134.39022.519866.759080@jerusalem.litteratus.org> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.32; amd64-portbld-freebsd12.0) X-Clacks-Overhead: "GNU Terry Pratchett" Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 48K23M4r06z40jS X-Spamd-Bar: - Authentication-Results: mx1.freebsd.org; dkim=pass header.d=email-od.com header.s=dkim header.b=E9lGPmmo; dmarc=none; 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 [-1.89 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-0.99)[-0.995,0]; R_DKIM_ALLOW(-0.20)[email-od.com:s=dkim]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; R_SPF_ALLOW(-0.20)[+ip4:142.0.176.0/20]; MV_CASE(0.50)[]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[sohara.org]; FORGED_SENDER_VERP_SRS(0.00)[]; TO_DN_SOME(0.00)[]; NEURAL_HAM_LONG(-1.00)[-0.999,0]; RCVD_COUNT_THREE(0.00)[4]; TO_MATCH_ENVRCPT_SOME(0.00)[]; DKIM_TRACE(0.00)[email-od.com:+]; RCVD_IN_DNSWL_NONE(0.00)[198.176.0.142.list.dnswl.org : 127.0.15.0]; ENVFROM_VERP(0.00)[]; IP_SCORE(0.11)[ip: (-0.30), ipnet: 142.0.176.0/22(0.59), asn: 7381(0.29), country: US(-0.05)]; FORGED_SENDER(0.00)[steve@sohara.org,4250.10.freebsd-questions=freebsd.org@email-od.com]; MIME_TRACE(0.00)[0:+]; RCVD_TLS_LAST(0.00)[]; ASN(0.00)[asn:7381, ipnet:142.0.176.0/22, country:US]; FROM_NEQ_ENVFROM(0.00)[steve@sohara.org,4250.10.freebsd-questions=freebsd.org@email-od.com]; MID_RHS_MATCH_FROM(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: Fri, 14 Feb 2020 18:29:36 -0000 On Fri, 14 Feb 2020 07:54:06 -0500 Robert Huff wrote: > _If_ that's true, then it's a bug and needs to be fixed. The > folks posting here may not need it ... but I find it hard to imagine > various organizations that use FreeBSD (or would like to) on hardcore > server hardware wouldn't find that a substantial liability. > While this may be more suited to hackers@: can anyone here > confirm there is an encoded limit on swap space? According to this there is (or was at the time) a hard coded limit of 32GB per swap device - just checked it's still there. You can of course have several swap devices - which is probably a very good idea if you actually need more than 32GB of swap. https://lists.freebsd.org/pipermail/freebsd-stable/2011-August/063529.html Relevant text: Anyway, there is one thing in /usr/src/sys/vm/swap_pager.c (so if you get this warning (reducing size to maximum of... per swap unit)), this might be the reason: /* * If we go beyond this, we get overflows in the radix * tree bitmap code. */ mblocks = 0x40000000 / BLIST_META_RADIX; if (nblks > mblocks) { printf("WARNING: reducing size to maximum of %lu blocks per swap unit\n", mblocks); nblks = mblocks; } -- Steve O'Hara-Smith