From owner-freebsd-fs@FreeBSD.ORG Fri Sep 17 16:47:34 2010 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 3B751106564A for ; Fri, 17 Sep 2010 16:47:34 +0000 (UTC) (envelope-from gvidals@gmail.com) Received: from mail-ey0-f182.google.com (mail-ey0-f182.google.com [209.85.215.182]) by mx1.freebsd.org (Postfix) with ESMTP id B51D18FC25 for ; Fri, 17 Sep 2010 16:47:33 +0000 (UTC) Received: by eyx24 with SMTP id 24so1343632eyx.13 for ; Fri, 17 Sep 2010 09:47:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:reply-to :in-reply-to:references:date:message-id:subject:from:to:content-type; bh=iqej5zkzuxskJkuwLuntFCneCblNXycHl9Gcqv77MLM=; b=prhi2Oaamf80nGZCdYtCwaiUq3tJEcpiiT37z2bl5EukfUPMPcnlj5R1u242W2AZC5 l+lpSVvvIrkB6qAqdGTDBeJSODNTNGoWa8iGfQsfnMxVXVwxDw6Z/tjDRK1IohIsWiOj jYemxIMXNMR62Dz75GRR8bTB7NRzV2hjj54Wo= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:reply-to:in-reply-to:references:date:message-id :subject:from:to:content-type; b=xqZe7dGnXkx4oHUMsL6BmrT+9E4ECJVJOAqI/fLPCnRHij+RqgiKd6OtdSiGhUGNaa CaAGiKcPJYHbScx/DfU4G/f1TltCoWXJFdqLVTwv+Hrr6WcHcAfndkfGbSM0dfl0UEvo NGR70LBjFs6GEUzukuh3bwwyxEuPdKFOk5MPg= MIME-Version: 1.0 Received: by 10.239.129.195 with SMTP id 3mr324469hbg.22.1284742052277; Fri, 17 Sep 2010 09:47:32 -0700 (PDT) Received: by 10.239.153.75 with HTTP; Fri, 17 Sep 2010 09:47:32 -0700 (PDT) In-Reply-To: References: <4C9385B0.2080909@shatow.net> <20100917161847.GA58503@icarus.home.lan> Date: Fri, 17 Sep 2010 09:47:32 -0700 Message-ID: From: Gil Vidals To: freebsd-fs@freebsd.org Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Subject: Re: what happens to pool if ZIL dies on ZFS v14 X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: gil@vidals.net List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 17 Sep 2010 16:47:34 -0000 First, let me say that I'm receiving excellent input from the FreeBSD community. I'm new to FreeBSD and ZFS and this mailing list has been very helpful. I'm running ZFSv14 on FreeBSD 8.1 AMD64 with 8GB of DDR3 RAM with two SSDs - one for the ZIL and the other for the L2ARC cache. zambia# zpool iostat -v 1 1 capacity operations bandwidth pool used avail read write read write ---------------- ----- ----- ----- ----- ----- ----- tank 6.57G 921G 0 11 116K 438K mirror 6.57G 921G 0 5 116K 229K label/disk1 - - 0 3 57.9K 229K label/disk2 - - 0 3 57.8K 229K label/zilcache 136K 59.5G 0 6 17 209K cache - - - - - - label/l2cache 59.6G 8.50K 0 0 31.5K 48.9K ---------------- ----- ----- ----- ----- ----- ----- Observing the ZIL Cache, I see it being used very sparingly. And now that I know the SSD slog must be mirrored in ZFS < v19, I think the best course of action (assuming I'm not buying more equipment) is to mirror the ZIL SSD and abandon the L2ARC altogether. Won't RAM be used for L2ARC instead? --Gil Vidals / VMRacks.com On Fri, Sep 17, 2010 at 9:21 AM, Freddie Cash wrote: > On Fri, Sep 17, 2010 at 9:18 AM, Jeremy Chadwick > wrote: > > On Fri, Sep 17, 2010 at 09:17:11AM -0700, Freddie Cash wrote: > >> On Fri, Sep 17, 2010 at 8:35 AM, Gil Vidals wrote: > >> > Bryan thank you for the detailed answer. > >> > > >> > Assuming the ZIL SSD died, what steps would I follow to recover the > pool? (i > >> > hope it is recoverable). > >> > >> If you are running ZFSv1 through ZFSv18 and your log device dies, your > >> pool is dead, gone, unrecoverable, no secret prize, no continues, do > >> not pass go, etc, etc, etc. > >> > >> If you are running ZFSv19 or newer and your log device dies, you can > >> remove the dead device and carry on. You will lose any data that was > >> in the ZIL, but the pool will be intact. > > > > Given the severity of this predicament, then why is it people are > > disabling the ZIL (via vfs.zfs.zil_disable=1) ? > > I'm not sure what you mean by that. > > This (dead ZIL == dead pool) only applies to separate log (slog) devices. > > -- > Freddie Cash > fjwcash@gmail.com > _______________________________________________ > 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" >