Mailing-List: contact core-user-help@hadoop.apache.org; run by ezmlm
Precedence: bulk
Reply-To: core-user@hadoop.apache.org
Received-SPF: neutral (athena.apache.org: local policy)
DomainKey-Signature: a=rsa-sha1; s=serpent; d=yahoo-inc.com; c=nofws; q=dns;
	h=received:user-agent:date:subject:from:to:message-id:
	thread-topic:thread-index:in-reply-to:mime-version:content-type:
	content-transfer-encoding:return-path:x-originalarrivaltime;
	b=z4wiQB1LUuWWMHl/MvSx0bwT1vzRT3Y4WUAOaIaSBygnGagsYI/0YjmhajjXssHD
User-Agent: Microsoft-Entourage/12.12.0.080729
Date: Tue, 14 Oct 2008 12:19:08 -0700
Subject: Re: getting HDFS to rack-aware mode
From: Hairong Kuang <hairong@yahoo-inc.com>
To: hadoop-user <core-user@hadoop.apache.org>
Message-ID: <C51A3EBC.B02B%hairong@yahoo-inc.com>
Thread-Topic: getting HDFS to rack-aware mode
Thread-Index: AckuMbrboyM+/MoggEST7mBhNN0HYA==
In-Reply-To: <c9690f720810141206u46b447a1w76e86b5cb142cdfe@mail.gmail.com>
Mime-version: 1.0
Content-type: text/plain;
	charset="US-ASCII"
Content-transfer-encoding: 7bit

Using -w option for the set replication command will wait until replication
is done. Then run fsck to check if the all blocks are on at least two racks.

Hairong


On 10/14/08 12:06 PM, "Sriram Rao" <sriramsrao@gmail.com> wrote:

> Hi,
> 
> We have a cluster where we running HDFS in non-rack-aware mode.  Now,
> we want to switch HDFS to run in rack-aware mode.  Apart from the
> config changes (and restarting HDFS), to rackify the existing data, we
> were thinking of increasing/decreasing replication level a few times
> to get the data spread.  Are there any tools that will enable us to
> know when we are "done"?
> 
> Sriram