From owner-freebsd-fs@freebsd.org Wed Jul 22 18:52:57 2015 Return-Path: Delivered-To: freebsd-fs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 58A4B9A81D6 for ; Wed, 22 Jul 2015 18:52:57 +0000 (UTC) (envelope-from javocado@gmail.com) Received: from mail-la0-x22c.google.com (mail-la0-x22c.google.com [IPv6:2a00:1450:4010:c03::22c]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id D610F161C; Wed, 22 Jul 2015 18:52:56 +0000 (UTC) (envelope-from javocado@gmail.com) Received: by lahh5 with SMTP id h5so143623261lah.2; Wed, 22 Jul 2015 11:52:54 -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; bh=lhIOxTeqlr5rT+sUGIIrk7Lk5VhRKPkH0WawPJx79hA=; b=txPoSh8HK4NYZgmEyuqhAe1w8nO59/Y6hTpNIfSBj0NbLJs1YtoKcCs4w6gPUa84Ca hscOfBjbd7lZo0/fp+aJGHjcqEZOaD3VsW7YDIcpg1E2IbmIOja41MIfvxe02CfoVGis 8bR8xc70LQ9WyuIxwa0ZVKvP2+oVb76aj4bT8FUY6xF2zbD9+Kq1kmheESmIXU7ehxSe 8+goiHfs7Cf0ecDBG4tmxs8aKoIl9Fce5Nag0JahJIJ+flwlRqYr2VXJiQQ98Hr+lG90 cBtYGizapDk86lpLKqrujuDkDjsS07YKeNmCd42ekI8l0LwOhEhYvxgsd3vDHm6XS6r5 YDIw== MIME-Version: 1.0 X-Received: by 10.112.40.66 with SMTP id v2mr3700309lbk.27.1437591174885; Wed, 22 Jul 2015 11:52:54 -0700 (PDT) Received: by 10.114.96.8 with HTTP; Wed, 22 Jul 2015 11:52:54 -0700 (PDT) In-Reply-To: <20150722003218.GD41419@in-addr.com> References: <20150722003218.GD41419@in-addr.com> Date: Wed, 22 Jul 2015 11:52:54 -0700 Message-ID: Subject: Re: Prioritize resilvering priority From: javocado To: Gary Palmer , michelle@sorbs.net Cc: FreeBSD Filesystems Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.20 X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 22 Jul 2015 18:52:57 -0000 Thanks for all that feedback. Yes, this is for zfs. It looks like some of those sysctls are not available in 8.3: # sysctl vfs.zfs.scrub_delay sysctl: unknown oid 'vfs.zfs.scrub_delay' # sysctl vfs.zfs.resilver_delay sysctl: unknown oid 'vfs.zfs.resilver_delay' # sysctl vfs.zfs.zfs_top_maxinflight sysctl: unknown oid 'vfs.zfs.zfs_top_maxinflight' But I do have: vfs.zfs.vdev.max_pending: 10 (dynamic) vfs.zfs.scrub_limit: 10 (loader) So, I think I would want to lower one or both of these to increase I/O responsiveness on the system. Correct? How would the 2 play together in terms of which to adjust to achieve the best system performance at the expense of a longer resilver? On Tue, Jul 21, 2015 at 5:32 PM, Gary Palmer wrote: > On Tue, Jul 21, 2015 at 04:06:05PM -0700, javocado wrote: > > Hi, > > > > How does one go about prioritizing the resilvering process so it does not > > overwhelm normal disk I/O on a FreeBSD (8.3amd) system? Further, can > this > > be altered in real time, or do the settings have to be in place prior to > > the resilvering even starting? > > You don't state, but is this on ZFS? > > I assume they're on 8.3 also, but look at settings like > vfs.zfs.resilver_min_time_ms and vfs.zfs.resilver_delay in sysctl. > Searching for resilver_min_time_ms and resilver_delay may give > some hints, e.g. > > > http://broken.net/uncategorized/zfs-performance-tuning-for-scrubs-and-resilvers/ > > does the opposite to what you want, but it should give hints. Also > > > https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/zfs-advanced.html > > I think they're dynamic. I tuned the scrub settings and they took effect > immediately. > > Regards, > > Gary >