From owner-freebsd-questions@FreeBSD.ORG Wed Nov 4 09:19:15 2009 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 30F62106566B for ; Wed, 4 Nov 2009 09:19:15 +0000 (UTC) (envelope-from kraduk@googlemail.com) Received: from mail-bw0-f213.google.com (mail-bw0-f213.google.com [209.85.218.213]) by mx1.freebsd.org (Postfix) with ESMTP id A81528FC19 for ; Wed, 4 Nov 2009 09:19:14 +0000 (UTC) Received: by bwz5 with SMTP id 5so8811970bwz.3 for ; Wed, 04 Nov 2009 01:19:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:cc:content-type; bh=Oksk2Fs3fE6BvOdP/DOveybhOVnX+8D7p2ElkH78wVc=; b=qZyVXBfUbPwU4OKXIzAt27Dewr7WUw8Zobv8cjdLeeViCcwwmL1NHuWe5nbzoj9e6j o1PA1/BYZUQ9KIda9cMWvfO1v8SuYPmbUKjGY7E+uMqaboCAR+x0KU0a+ka1tn41RJT/ rtO/BmsvVavyjkj3of/4mxTw4kGAFje/mI17g= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=GYEFxiW4nkN/zNONWzB5Gu5AptrqGkGE7cbwel+xQ35DEsB8whnhal1qbCEPoooFCK oBCadxa4tLa3ofzA4zwQTsYLuCBfU6dh9xyxOzHpwXHkxHw+wtwd79j1poFXk/pS3TWx Deh4LFKYMfYToVdbSVe0WatzMDiHLsNKxvXwk= MIME-Version: 1.0 Received: by 10.239.168.195 with SMTP id l3mr130191hbe.27.1257326353571; Wed, 04 Nov 2009 01:19:13 -0800 (PST) In-Reply-To: <4AF08A42.9000900@comcast.net> References: <4AF07493.7050208@comcast.net> <4AF08A42.9000900@comcast.net> Date: Wed, 4 Nov 2009 09:19:13 +0000 Message-ID: From: krad To: Steve Polyack Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: Derrick Ryalls , FreeBSD Questions Subject: Re: ZFS disk replacement questions X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 04 Nov 2009 09:19:15 -0000 2009/11/3 Steve Polyack > Derrick Ryalls wrote: > >> On Tue, Nov 3, 2009 at 10:21 AM, Steve Polyack >> wrote: >> >> >>> Derrick Ryalls wrote: >>> >>> >>>> 1) In the event of a disk failure, how do I trace back the name such >>>> as adX to a physical drive in the enclosure? Is there a way to take >>>> the drive offline then use atacontrol to spin it down or something so >>>> it is easy to identify? >>>> >>>> >>>> >>> In my opinion you are best off using glabel(8) to give names to the >>> disks. >>> This way you can name them in a way that makes sense to you. >>> Additionally, >>> when you create the ZFS pool you will use the glabel'd names. This means >>> that the pool will still come up properly if something causes your >>> devices >>> to be numbered differently (i.e. a drive dies and you happen to reboot >>> the >>> system). >>> >>> >> >> I believe ZFS does this automatically. Supposedly, if you take a >> working set of RAIDZ drives from one machine and put it in another, >> ZFS will figure out the drives since they get labelled by ZFS >> internally. My question concerns how to identify the physical disk in >> question based on the adX or glabel name? Different name in software >> is fine, but if the drive fails I want to make sure I pull the correct >> drive. >> >> >> > This is possible, but I don't remember reading that ZFS handles this > anywhere, and I've seen glabel(8) recommended elsewhere for the same reason. > > Either way, you can add your drives one-by-one and label them on the > enclosure "arraydrive00" and then glabel the individual disks with the same > name. This way when ZFS tells you "arraydrive03" is dead/offline, you can > look at your enclosure and pull the drive with the arraydrive03 label. > > Depending on your controller it is also probably worth it to use one of >>> the >>> SATA-specific drivers in FreeBSD 8 - these are ones like ahci(4) and >>> siis(4). While the generic ata(4) driver will work for pretty much >>> everything, the updated AHCI drivers can take advantage of some more >>> features. Enable the modules at boot to use them. >>> >>> >> >> I will look into it, thanks. The machine in question is 2 year old >> hardware currently with a 3ware raid card. I will be going software >> raid only, but FreeBSD already recognizes the eSATA drive I have >> attached as a backup device so I know the O/S can at least talk to >> sata drives attached to the mobo. >> >> >> > > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to " > freebsd-questions-unsubscribe@freebsd.org" > One thing to note about resilvering; unlike most raid systems zfs knows what is going on at the filesystem level as well as block level. Therefore when a drive has to be resilvered, only the data on the drive is rebuilt rather than every block as with most other raid subsystems. eg if you have a 1TB hd but only have 20 Gig of data, only 20 gig is copied/rebuilt rather than 1 TB of data if you were using gvinum/gmirror. This massively speeds up rebuild times and stress on the other drives. However the fuller the drive the less the benefits