From owner-freebsd-fs@freebsd.org Wed Jul 22 00:46:22 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 A2D969A7F46 for ; Wed, 22 Jul 2015 00:46:22 +0000 (UTC) (envelope-from michelle@sorbs.net) Received: from hades.sorbs.net (hades.sorbs.net [67.231.146.201]) by mx1.freebsd.org (Postfix) with ESMTP id 949B51D1D; Wed, 22 Jul 2015 00:46:22 +0000 (UTC) (envelope-from michelle@sorbs.net) MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: text/plain; CHARSET=US-ASCII Received: from isux.com (firewall.isux.com [213.165.190.213]) by hades.sorbs.net (Oracle Communications Messaging Server 7.0.5.29.0 64bit (built Jul 9 2013)) with ESMTPSA id <0NRV00B536F58K00@hades.sorbs.net>; Tue, 21 Jul 2015 17:52:19 -0700 (PDT) Message-id: <55AEE7DB.1030609@sorbs.net> Date: Wed, 22 Jul 2015 02:46:19 +0200 From: Michelle Sullivan User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X; en-US; rv:1.8.1.24) Gecko/20100301 SeaMonkey/1.1.19 To: Gary Palmer Cc: javocado , FreeBSD Filesystems Subject: Re: Prioritize resilvering priority References: <20150722003218.GD41419@in-addr.com> In-reply-to: <20150722003218.GD41419@in-addr.com> 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 00:46:22 -0000 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. > > They mostly the settings are dynamic (both the ones you have above are) ... at worst some settings only take effect at boot time, so if you wanted to change them reboot. None of the settings have to be made before resilvering commences (remember that when you reboot, the resilver stops then is resumed on startup so any 'boot tunables' take effect) -- Michelle Sullivan http://www.mhix.org/