From owner-freebsd-fs@freebsd.org Tue May 11 17:09:53 2021 Return-Path: Delivered-To: freebsd-fs@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 D113763EA3E for ; Tue, 11 May 2021 17:09:53 +0000 (UTC) (envelope-from pete@nomadlogic.org) Received: from mail.nomadlogic.org (mail.nomadlogic.org [66.165.241.226]) (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 "mail.nomadlogic.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4Ffktm4zCBz4ZtF for ; Tue, 11 May 2021 17:09:52 +0000 (UTC) (envelope-from pete@nomadlogic.org) Received: from [192.168.1.223] (cpe-24-24-163-126.socal.res.rr.com [24.24.163.126]) by mail.nomadlogic.org (OpenSMTPD) with ESMTPSA id b22d9673 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO) for ; Tue, 11 May 2021 17:09:44 +0000 (UTC) To: freebsd-fs@freebsd.org From: Pete Wright Subject: Changes in vfs.zfs.arc_max on 13 Message-ID: <0961dfe0-922e-8a6f-0bf9-c0685e3ec3d1@nomadlogic.org> Date: Tue, 11 May 2021 10:09:43 -0700 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 Content-Language: en-US X-Rspamd-Queue-Id: 4Ffktm4zCBz4ZtF X-Spamd-Bar: --- X-Spamd-Result: default: False [-4.00 / 15.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; R_DKIM_ALLOW(-0.20)[nomadlogic.org:s=04242021]; MID_RHS_MATCH_FROM(0.00)[]; FROM_HAS_DN(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; R_SPF_ALLOW(-0.20)[+mx]; MIME_GOOD(-0.10)[multipart/alternative,text/plain]; TO_DN_NONE(0.00)[]; PREVIOUSLY_DELIVERED(0.00)[freebsd-fs@freebsd.org]; RCPT_COUNT_ONE(0.00)[1]; SPAMHAUS_ZRD(0.00)[66.165.241.226:from:127.0.2.255]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; DKIM_TRACE(0.00)[nomadlogic.org:+]; DMARC_POLICY_ALLOW(-0.50)[nomadlogic.org,quarantine]; NEURAL_HAM_SHORT(-1.00)[-0.997]; NEURAL_HAM_LONG(-1.00)[-1.000]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+,1:+,2:~]; RBL_DBL_DONT_QUERY_IPS(0.00)[66.165.241.226:from]; ASN(0.00)[asn:29802, ipnet:66.165.240.0/22, country:US]; RCVD_TLS_ALL(0.00)[]; MAILMAN_DEST(0.00)[freebsd-fs]; RCVD_COUNT_TWO(0.00)[2] Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-Content-Filtered-By: Mailman/MimeDel 2.1.34 X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 11 May 2021 17:09:53 -0000 Hello, I have a handful of systems running both 13.0-REL and 13-STABLE and have noticed a few deviations from what I've found in the handbook in regards to the vfs.zfs.arc_max sysctl knob.  I am referring to this section of the Handbook: https://docs.freebsd.org/en/books/handbook/zfs/ I see a handful of references to using vfs.zfs.arc_max, but when run on my 13.x systems it states this knob is legacy: $ sysctl -d vfs.zfs.arc_max vfs.zfs.arc_max: max arc size (LEGACY) It seems the preferred method moving forward is to use vfs.zfs.arc.max.  No biggie there, I am happy to submit an update PR to the handbook for that. The next issue I am seeing is that when setting this variable the example from the handbook states you can do something similar to this (section 20.6.2.3): vfs.zfs.arc_max="40M" This throws an error on my system: $ sudo sysctl vfs.zfs.arc_max=2048M sysctl: invalid unsigned long '2048M' $ sudo sysctl vfs.zfs.arc_max=2G sysctl: invalid unsigned long '2G' Using the human unfriendly form works though: $ sudo sysctl vfs.zfs.arc.max="2000000000" vfs.zfs.arc.max: 0 -> 2000000000 $ Is this a bug, or would it be best to also update the documentation accordingly to reflect this? Personally I like the old behavior as it's easier on my eyes. Thanks! -pete -- Pete Wright pete@nomadlogic.org @nomadlogicLA