From owner-freebsd-questions@freebsd.org Wed Feb 13 17:12:04 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 3F74F14D1A47 for ; Wed, 13 Feb 2019 17:12:04 +0000 (UTC) (envelope-from steve@sohara.org) Received: from smtp1.irishbroadband.ie (smtp2.irishbroadband.ie [62.231.32.43]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 8C5836C2AF for ; Wed, 13 Feb 2019 17:11:53 +0000 (UTC) (envelope-from steve@sohara.org) Received: from [89.127.62.20] (helo=smtp.lan.sohara.org) by smtp1.irishbroadband.ie with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1gty4V-0003Qa-Tw for freebsd-questions@freebsd.org; Wed, 13 Feb 2019 17:11:44 +0000 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 1gty4V-000Hyd-7O for freebsd-questions@freebsd.org; Wed, 13 Feb 2019 17:11:43 +0000 Date: Wed, 13 Feb 2019 17:11:42 +0000 From: Steve O'Hara-Smith To: freebsd-questions@freebsd.org Subject: Re: ZFS and a spare SSD: ZIL or L2ARC? Message-Id: <20190213171142.33b7c430c5ec256b1cbafa42@sohara.org> In-Reply-To: References: 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: 8C5836C2AF X-Spamd-Bar: +++ Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [3.46 / 15.00]; ARC_NA(0.00)[]; FROM_HAS_DN(0.00)[]; MV_CASE(0.50)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; MIME_TRACE(0.00)[0:+]; TO_DN_NONE(0.00)[]; AUTH_NA(1.00)[]; RCPT_COUNT_ONE(0.00)[1]; RCVD_COUNT_THREE(0.00)[3]; RCVD_TLS_LAST(0.00)[]; NEURAL_SPAM_SHORT(0.07)[0.068,0]; MX_GOOD(-0.01)[mxbackup1.junkemailfilter.com,mxbackup2.junkemailfilter.com,mail.sohara.org,mxbackup1.junkemailfilter.com,mxbackup2.junkemailfilter.com,mail.sohara.org,mxbackup1.junkemailfilter.com,mxbackup2.junkemailfilter.com,mail.sohara.org,mxbackup1.junkemailfilter.com,mxbackup2.junkemailfilter.com,mail.sohara.org,mxbackup1.junkemailfilter.com,mxbackup2.junkemailfilter.com,mail.sohara.org,mxbackup1.junkemailfilter.com,mxbackup2.junkemailfilter.com,mail.sohara.org,mxbackup1.junkemailfilter.com,mxbackup2.junkemailfilter.com,mail.sohara.org,mxbackup1.junkemailfilter.com,mxbackup2.junkemailfilter.com,mail.sohara.org]; NEURAL_SPAM_LONG(0.64)[0.642,0]; DMARC_NA(0.00)[sohara.org]; NEURAL_SPAM_MEDIUM(0.46)[0.462,0]; R_SPF_NA(0.00)[]; RCVD_IN_DNSWL_LOW(-0.10)[43.32.231.62.list.dnswl.org : 127.0.5.1]; R_DKIM_NA(0.00)[]; SUBJECT_ENDS_QUESTION(1.00)[]; ASN(0.00)[asn:25441, ipnet:62.231.32.0/19, country:IE]; MID_RHS_MATCH_FROM(0.00)[]; IP_SCORE(-0.00)[country: IE(-0.01)]; FROM_EQ_ENVFROM(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: Wed, 13 Feb 2019 17:12:04 -0000 On Wed, 13 Feb 2019 18:02:51 +0100 Andrea Venturoli wrote: > Now I've just got hold of a spare SSD and, although the box performance > is adequate, I'd like to see if it can boost it. > Should I configure it as L2ARC? ZIL? Both? In my experience L2ARC tends to run full and ZIL uses almost none of the space allocated. But then my workload is read heavy - for a write heavy workload ZIL is probably more beneficial. -- Steve O'Hara-Smith