From general-return-1133-apmail-hadoop-general-archive=hadoop.apache.org@hadoop.apache.org Tue Mar 02 00:09:03 2010 Return-Path: Delivered-To: apmail-hadoop-general-archive@minotaur.apache.org Received: (qmail 73829 invoked from network); 2 Mar 2010 00:09:02 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 2 Mar 2010 00:09:02 -0000 Received: (qmail 26330 invoked by uid 500); 2 Mar 2010 00:09:00 -0000 Delivered-To: apmail-hadoop-general-archive@hadoop.apache.org Received: (qmail 26298 invoked by uid 500); 2 Mar 2010 00:09:00 -0000 Mailing-List: contact general-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: general@hadoop.apache.org Delivered-To: mailing list general@hadoop.apache.org Received: (qmail 26290 invoked by uid 99); 2 Mar 2010 00:08:59 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 02 Mar 2010 00:08:59 +0000 X-ASF-Spam-Status: No, hits=2.2 required=10.0 tests=HTML_MESSAGE,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: domain of mvgfr1@gmail.com designates 209.85.211.199 as permitted sender) Received: from [209.85.211.199] (HELO mail-yw0-f199.google.com) (209.85.211.199) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 02 Mar 2010 00:08:51 +0000 Received: by ywh37 with SMTP id 37so1757932ywh.2 for ; Mon, 01 Mar 2010 16:08:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type; bh=gE61MftzCaWHS1bhGkGtjcC8Lj7Ebe6/RK8MxVhnBwM=; b=knCI8h1NJJXazkZ3VRdd7MPvj6pL4r8sB83fYSXWSeip+YG3XcCEek1uHhuDpRDj31 W4Ydx3LCjDND015mIuWlpRvYngGTFdvn3fQGNq9wSNe0FE3tjdA1kwjOP+aSO5dNWZfn ycC7K/iteRPtmgxSSF5jilNDdoBn8R5D+xl8g= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=SX45OnBJ4WHNrpkYMop5h4+MbyRln76pYMb6nNEoBtUSdLFNaoTd1qsIcwIQsHoKNI /R0U/2F2863bdZbJGLwyrOxD4CKCtkj8J0s83WJ11OZDx9qRhydznJSYrbihNa/TD1GJ /5xaTs8dca6eMrS4Q38abkMFKsdyGtpLoA1UU= MIME-Version: 1.0 Received: by 10.151.24.21 with SMTP id b21mr7471855ybj.201.1267488510773; Mon, 01 Mar 2010 16:08:30 -0800 (PST) In-Reply-To: References: <1703587b1002281345k118d980al3ec458cd0d74d343@mail.gmail.com> <4c7b1781002281418k578fabb4n81778bb0890e5c90@mail.gmail.com> <4c7b1781003010819v61f9a792t2ac7c8bba2ec4964@mail.gmail.com> Date: Mon, 1 Mar 2010 19:08:30 -0500 Message-ID: <4c7b1781003011608r40cb6a91vaf6c88e852508032@mail.gmail.com> Subject: Re: Adding hard-disks to an existing HDFS cluster From: Marc Farnum Rendino To: general@hadoop.apache.org Content-Type: multipart/alternative; boundary=000e0cd297a8710aec0480c62a8b X-Virus-Checked: Checked by ClamAV on apache.org --000e0cd297a8710aec0480c62a8b Content-Type: text/plain; charset=ISO-8859-1 On Mon, Mar 1, 2010 at 2:00 PM, Eli Collins wrote: > Yes, it's good to have multiple directories as well as may each or at > least some of the directories reliable, eg below > /data//dfs/namenode are local disks and /mnt/filer-hdfs is a > reliable NFS filer. > > dfs.name.dir > > /data/1/dfs/namenode,/data/2/dfs/namenode,/mnt/filer-hdfs/dfs/namenode > Ah; nice - preciate the clarification. > You also of course want to run a secondary namenode (2NN), though > that's more to keep the edits log size (and restart time) manageable > rather than for reliability purposes. Having a 2NN on a separate host > does act as a backup of your NN metadata, though it will always be out > of date. But that's one of those "better than the alternative" situations. :) > There's work on trunk to add a backup name node which gets a > stream of edits from the NN so it has an update copy of the metadata. > Ah; I think this is alluded to in the conf file, right? - Marc --000e0cd297a8710aec0480c62a8b--