From owner-freebsd-fs@FreeBSD.ORG Wed Jan 9 05:51:28 2013 Return-Path: Delivered-To: freebsd-fs@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id B239FA13; Wed, 9 Jan 2013 05:51:28 +0000 (UTC) (envelope-from hrs@FreeBSD.org) Received: from mail.allbsd.org (gatekeeper.allbsd.org [IPv6:2001:2f0:104:e001::32]) by mx1.freebsd.org (Postfix) with ESMTP id 85570283; Wed, 9 Jan 2013 05:51:24 +0000 (UTC) Received: from alph.allbsd.org (p1137-ipbf1505funabasi.chiba.ocn.ne.jp [118.7.212.137]) (authenticated bits=128) by mail.allbsd.org (8.14.5/8.14.5) with ESMTP id r095oqTS004318 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 9 Jan 2013 14:51:09 +0900 (JST) (envelope-from hrs@FreeBSD.org) Received: from localhost (localhost [127.0.0.1]) (authenticated bits=0) by alph.allbsd.org (8.14.5/8.14.5) with ESMTP id r095ooJx010464; Wed, 9 Jan 2013 14:50:51 +0900 (JST) (envelope-from hrs@FreeBSD.org) Date: Wed, 09 Jan 2013 14:09:46 +0900 (JST) Message-Id: <20130109.140946.1818513049591807609.hrs@allbsd.org> To: jwd@FreeBSD.org Subject: Re: rc.d script for memory based zfs intent log From: Hiroki Sato In-Reply-To: <20130109031834.GA14386@FreeBSD.org> References: <20130109023327.GA1888@FreeBSD.org> <20130109.115240.1198411557684741197.hrs@allbsd.org> <20130109031834.GA14386@FreeBSD.org> X-PGPkey-fingerprint: BDB3 443F A5DD B3D0 A530 FFD7 4F2C D3D8 2793 CF2D X-Mailer: Mew version 6.5 on Emacs 23.4 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Multipart/Signed; protocol="application/pgp-signature"; micalg=pgp-sha1; boundary="--Security_Multipart(Wed_Jan__9_14_09_46_2013_178)--" Content-Transfer-Encoding: 7bit X-Virus-Scanned: clamav-milter 0.97.4 at gatekeeper.allbsd.org X-Virus-Status: Clean X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.7 (mail.allbsd.org [133.31.130.32]); Wed, 09 Jan 2013 14:51:10 +0900 (JST) X-Spam-Status: No, score=-98.1 required=13.0 tests=CONTENT_TYPE_PRESENT, ONLY1HOPDIRECT,SAMEHELOBY2HOP,USER_IN_WHITELIST autolearn=no version=3.3.2 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on gatekeeper.allbsd.org Cc: freebsd-fs@FreeBSD.org X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 09 Jan 2013 05:51:28 -0000 ----Security_Multipart(Wed_Jan__9_14_09_46_2013_178)-- Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit John wrote in <20130109031834.GA14386@FreeBSD.org>: jw> ----- Hiroki Sato's Original Message ----- jw> > John wrote jw> > in <20130109023327.GA1888@FreeBSD.org>: jw> > jw> > jw> Hi Folks, jw> > jw> jw> > jw> Here's an rc.d script that provides a nice performance boost on jw> > jw> ZFS/NFS based file servers. It also helps in other areas not specific jw> > jw> to NFS. jw> > jw> jw> > jw> It attaches the log device at system startup and removes it at jw> > jw> system shutdown time. Example; jw> > jw> jw> > jw> memzil_pools="tank" jw> > jw> memzil_bootfs="YES" jw> > jw> service memzil onestart jw> > jw> zpool status tank jw> > jw> service memzil onestop jw> > jw> jw> > jw> This configuration provides a nice performance boost especially to jw> > jw> NFS, but also helps in other areas not specific to NFS. jw> > jw> jw> > jw> Please DO NOT USE this script if your system is not UPS backed, preferably jw> > jw> with dual power supplies on separate circuits. If your system crashes you jw> > jw> may lose data. The script contains information on recovery. jw> > jw> jw> > jw> http://people.freebsd.org/~jwd/memzil.txt jw> > jw> jw> > jw> Comments/Improvements appreciated. jw> > jw> > Why is simply setting sync=disabled to the ZFS dataset not enough? jw> jw> As you refer to, my understanding is that sync=disabled is at the dataset jw> layer. The zil approach is at the zpool layer - sync=disabled would be jw> nice at the zpool layer. Can you elaborate why it matters? If one wants to disable ZIL, just setting sync=disabled should be enough. Using memory disk to effectively disable ZIL on physical HDDs looks a roundabout way to do the same thing to me. -- Hiroki ----Security_Multipart(Wed_Jan__9_14_09_46_2013_178)-- Content-Type: application/pgp-signature Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (FreeBSD) iEYEABECAAYFAlDs+5oACgkQTyzT2CeTzy2KIgCdFLIlCEFI9Bfz0CegX4BCEst7 FwEAnjgrEkumnADWyLUIa1xr29vN3C8g =1Ic7 -----END PGP SIGNATURE----- ----Security_Multipart(Wed_Jan__9_14_09_46_2013_178)----