From nobody Thu Feb 02 23:40:07 2023 X-Original-To: hackers@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 4P7Fdv272Bz3kjRB for ; Thu, 2 Feb 2023 23:40:35 +0000 (UTC) (envelope-from eugen@grosbein.net) Received: from hz.grosbein.net (hz.grosbein.net [IPv6:2a01:4f8:c2c:26d8::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "hz.grosbein.net", Issuer "hz.grosbein.net" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4P7Fdt3rlhz3kQH for ; Thu, 2 Feb 2023 23:40:34 +0000 (UTC) (envelope-from eugen@grosbein.net) Authentication-Results: mx1.freebsd.org; none Received: from eg.sd.rdtc.ru (root@eg.sd.rdtc.ru [62.231.161.221] (may be forged)) by hz.grosbein.net (8.16.1/8.16.1) with ESMTPS id 312NeVYU098639 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 2 Feb 2023 23:40:31 GMT (envelope-from eugen@grosbein.net) X-Envelope-From: eugen@grosbein.net X-Envelope-To: jbo@insane.engineer Received: from [10.58.0.11] (dadvw [10.58.0.11] (may be forged)) by eg.sd.rdtc.ru (8.16.1/8.16.1) with ESMTPS id 312NeUJd003594 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT); Fri, 3 Feb 2023 06:40:30 +0700 (+07) (envelope-from eugen@grosbein.net) Subject: Re: Swap, ZFS & ARC To: jbo@insane.engineer, "hackers@freebsd.org" References: <1689ba8c-a317-ce1f-2854-99566468a9ed@grosbein.net> From: Eugene Grosbein Message-ID: <5149591a-1bd8-c3e8-eaea-fc08808f1b0f@grosbein.net> Date: Fri, 3 Feb 2023 06:40:07 +0700 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 List-Id: Technical discussions relating to FreeBSD List-Archive: https://lists.freebsd.org/archives/freebsd-hackers List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-hackers@freebsd.org MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED,SHORTCIRCUIT autolearn=disabled version=3.4.6 X-Spam-Report: * -0.0 SHORTCIRCUIT No description available. * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on hz.grosbein.net X-Rspamd-Queue-Id: 4P7Fdt3rlhz3kQH X-Spamd-Bar: ---- X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; ASN(0.00)[asn:24940, ipnet:2a01:4f8::/32, country:DE] X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-ThisMailContainsUnwantedMimeParts: N 02.02.2023 22:45, jbo@insane.engineer wrote: >> 02.02.2023 21:28, jbo@insane.engineer wrote: >> >>> Hello folks, >>> >>> Based on a discussion on the forums not so long ago I tried to figure out how swap usage on a ZFS system plays together with ARC. However, I could find very little to no information on this which leads me to believe that there is some "core concept" I might be oblivious to. >>> >>> The main question is basically this: Your system starts to swap out data from RAM to your swap partition. >>> This swap data on disk ultimately resides somewhere in a ZFS pool. >> >> >> I prefer not doing this. That is, all my systems have swap partition outside of ZFS pool. > > This isn't really achievable on your average "single disk" desktop systems, right? For desktop systems you must use GPT/MBR to boot off single disk and with partitioning there is no problem in creating dedicated slice for swap.