From owner-freebsd-fs@FreeBSD.ORG Tue May 8 21:33:24 2012 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id F1684106564A for ; Tue, 8 May 2012 21:33:24 +0000 (UTC) (envelope-from fjwcash@gmail.com) Received: from mail-qa0-f47.google.com (mail-qa0-f47.google.com [209.85.216.47]) by mx1.freebsd.org (Postfix) with ESMTP id A8D5C8FC08 for ; Tue, 8 May 2012 21:33:24 +0000 (UTC) Received: by qabg1 with SMTP id g1so1160854qab.13 for ; Tue, 08 May 2012 14:33:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; bh=5k1em8eZqrWYkKiV39ucmQEHlrRO1LxzE/7T00pGiBI=; b=GWJEM3ebZfcZOqdP0xJnRmOVMp//i82WkU7ETSgvh6dybgM4uhMwaz9q7mveybRsOG X/4t7AX0pYDdIefM6h8e+uwIj36Io+CwSAab5Rnqtiskk8QmWN1fxet3oSupXXj2+pur zi/kxxwDoemBYKa2AYMBJwFoX2Rh5f5F/4jgqi3Vhh1ZXSgftxzrTybY0aNikCD1s2Kt c2RIRlasu6m6KS93vCmIkQ7S39Vqhk+RuamhUmKPdR8Dyb97ZR38HUHKvANioTjB0cuU rkBc7ZpZPBOnhzKwI/tfHn9fEUpWC+xTrA43FZ4if/5wEHppp2DMh8ROq44XopDjHL/F nK5g== MIME-Version: 1.0 Received: by 10.224.178.9 with SMTP id bk9mr932141qab.98.1336512804006; Tue, 08 May 2012 14:33:24 -0700 (PDT) Received: by 10.229.224.147 with HTTP; Tue, 8 May 2012 14:33:23 -0700 (PDT) In-Reply-To: References: <73F8D020-04F3-44B2-97D4-F08E3B253C32@grem.de> <180B72CE-B285-4702-B16D-0714AA07022C@grem.de> Date: Tue, 8 May 2012 14:33:23 -0700 Message-ID: From: Freddie Cash To: Bob Friesenhahn Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: freebsd-fs@freebsd.org, Michael Gmelin Subject: Re: ZFS resilvering strangles IO X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 08 May 2012 21:33:25 -0000 On Tue, May 8, 2012 at 2:31 PM, Bob Friesenhahn wrote: > On Tue, 8 May 2012, Michael Gmelin wrote: >> >> Do you think it would make sense to try to play with zfs_resilver_delay >> directly in the ZFS kernel module? > > This may be the wrong approach if the issue is really that there are too > many I/Os queued for the device. =C2=A0Finding a tunable which reduces th= e > maximum number of I/Os queued for a disk device may help reduce write > latencies by limiting the backlog. > > On my Solaris 10 system, I accomplished this via a tunable in /etc/system= : > set zfs:zfs_vdev_max_pending =3D 5 > > What is the equivalent for FreeBSD? Setting vfs.zfs.vdev_max_pending=3D"4" in /boot/loader.conf (or whatever value you want). The default is 10. > Bob > -- > Bob Friesenhahn > bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen= / > GraphicsMagick Maintainer, =C2=A0 =C2=A0http://www.GraphicsMagick.org/ > _______________________________________________ > freebsd-fs@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org" --=20 Freddie Cash fjwcash@gmail.com