Return-Path: X-Original-To: apmail-accumulo-user-archive@www.apache.org Delivered-To: apmail-accumulo-user-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 0668A9BC8 for ; Mon, 13 Aug 2012 16:31:48 +0000 (UTC) Received: (qmail 20774 invoked by uid 500); 13 Aug 2012 16:31:47 -0000 Delivered-To: apmail-accumulo-user-archive@accumulo.apache.org Received: (qmail 20724 invoked by uid 500); 13 Aug 2012 16:31:47 -0000 Mailing-List: contact user-help@accumulo.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@accumulo.apache.org Delivered-To: mailing list user@accumulo.apache.org Received: (qmail 20713 invoked by uid 99); 13 Aug 2012 16:31:47 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 13 Aug 2012 16:31:47 +0000 X-ASF-Spam-Status: No, hits=1.8 required=5.0 tests=FREEMAIL_ENVFROM_END_DIGIT,FSL_RCVD_USER,HTML_MESSAGE,RCVD_IN_DNSWL_LOW,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: domain of aji1705@gmail.com designates 209.85.214.169 as permitted sender) Received: from [209.85.214.169] (HELO mail-ob0-f169.google.com) (209.85.214.169) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 13 Aug 2012 16:31:39 +0000 Received: by obhx4 with SMTP id x4so8426153obh.0 for ; Mon, 13 Aug 2012 09:31:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:date:message-id:subject:from:to:content-type; bh=ymZkwsHtFqQBCQ5L/FcCd5CYXafVLByiUc3NfEXn8AQ=; b=Pbwq4QM4bNhH5KrYhaUukTrxl7TVqINjUYWSeZpIAhGsZWPPUlNnp1RNOBFcjdNQwU lLmCRHJhTfs+4g1MxnlPmIdT3nIAq9SoTk8ckzheDUYl5E3FLMsjppCe3HNEVCB7K08k 6Q0hJc3vxyaZfajPR+gQmSRo53Sf3hBaXYhP4/wS9TVHjyn/sKsDYfCcyIAtzL6ISsys IgSu/jCUdJ7aQucFUS2MVV1VlmabVbLPKP9RX+PaaE6O5bdNzXlooObBOcyBi1NfM7J/ Tqa/+k8p+suHtDWv+ijjOAJlnPBN6/3VMS44Em8OZ2BKxLwzCCMp2HJftHG5bIjLq2tN W0vg== MIME-Version: 1.0 Received: by 10.182.14.36 with SMTP id m4mr13134204obc.71.1344875478197; Mon, 13 Aug 2012 09:31:18 -0700 (PDT) Received: by 10.182.232.101 with HTTP; Mon, 13 Aug 2012 09:31:18 -0700 (PDT) Date: Mon, 13 Aug 2012 12:31:18 -0400 Message-ID: Subject: Hardware failure and data protection From: Aji Janis To: user@accumulo.apache.org Content-Type: multipart/alternative; boundary=14dae9399b4d25259304c728399d --14dae9399b4d25259304c728399d Content-Type: text/plain; charset=ISO-8859-1 I am very new to Hadoop and Accumulo. I need some information on how data is backed up or guaranteed against system failures (if it is).I am considering setting up a Hadoop cluster consisting of 5 nodes where each node has 3 internal hard drives. I understand HDFS has a configurable redundancy feature but what happens if an entire drive crashes (physically) for whatever reason? How does Hadoop recover, if it can, from this situation? More specifically, I am assuming Accumulo uses HDFS redundancy to make back ups of the data. One, is this assumption true? Two, if I had a copy of the hard drive and I duplicate that to a new drive and pop it in where the old/crashed drive used to be would this work? I apologize if this is a really stupid question. But I highly appreciate any help, pointers and suggestions! Thanks in advance. --14dae9399b4d25259304c728399d Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable I am very new to Hadoop and Accumulo. I need some information on how data i= s backed up or guaranteed against system failures (if it is).I am considering setting=A0up a Ha= doop cluster consisting of 5 nodes where each node has 3 internal hard driv= es. I understand HDFS has a configurable redundancy feature but what happen= s if an entire drive crashes (physically) for whatever reason? How does Had= oop recover, if it can, from this situation? More specifically, I am assumi= ng Accumulo uses HDFS redundancy to make back ups of the data.=A0
One, is this assum= ption true?
Two, if I had a= copy of the hard drive and I duplicate that to a new drive and pop it in w= here the old/crashed drive used to be would this work?

= I apologize if this is a really stupid question. But I highly appreciate an= y help, pointers and suggestions! Thanks in advance.
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