Mailing-List: contact user-help@hadoop.apache.org; run by ezmlm
Precedence: bulk
Reply-To: user@hadoop.apache.org
Received-SPF: pass (nike.apache.org: domain of harsh@cloudera.com designates
 209.85.210.180 as permitted sender)
MIME-Version: 1.0
In-Reply-To: <518261E7.8020606@doopai.com>
References: <518261E7.8020606@doopai.com>
From: Harsh J <harsh@cloudera.com>
Date: Thu, 2 May 2013 18:49:51 +0530
Message-ID: 
 <CAOcnVr2uDSZHrhDvdfEDAnPgc7Xiz2jUwuqd8va793PuXB0W8g@mail.gmail.com>
Subject: Re: How to restore HDFS data
To: "<user@hadoop.apache.org>" <user@hadoop.apache.org>
Content-Type: multipart/alternative; boundary=90e6ba5bbaa31c09eb04dbbc18c0

--90e6ba5bbaa31c09eb04dbbc18c0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

If you've already run -delete (-move is a better choice if you know DN
fault is temporary), then the missing blocks are already deleted from the
namespace permanently. No way to recover the data since the blocks have
also been invalidated by now.

A HDFS Snapshots feature will arrive in near future to cover the backup
scenarios that may prove useful in cases such as this.


On Thu, May 2, 2013 at 6:23 PM, =E6=AE=B5=E6=B4=AA=E4=B9=89 <duanhongyi@doo=
pai.com> wrote:

> Datanode error, and then I run hadoop fsck /-delete.Lost a lot of data,
> Later, these datanode recovery, Is there any way to restore the fsck
> command to delete the data.
>


--=20
Harsh J

--90e6ba5bbaa31c09eb04dbbc18c0
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr">If you&#39;ve already run -delete (-move is a better choic=
e if you know DN fault is temporary), then the missing blocks are already d=
eleted from the namespace permanently. No way to recover the data since the=
 blocks have also been invalidated by now.<div>

<br></div><div style>A HDFS Snapshots feature will arrive in near future to=
 cover the backup scenarios that may prove useful in cases such as this.</d=
iv></div><div class=3D"gmail_extra"><br><br><div class=3D"gmail_quote">On T=
hu, May 2, 2013 at 6:23 PM, =E6=AE=B5=E6=B4=AA=E4=B9=89 <span dir=3D"ltr">&=
lt;<a href=3D"mailto:duanhongyi@doopai.com" target=3D"_blank">duanhongyi@do=
opai.com</a>&gt;</span> wrote:<br>

<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex">Datanode error, and then I run hadoop fsck /=
-delete.Lost a lot of data,<br>
Later, these datanode recovery, Is there any way to restore the fsck<br>
command to delete the data.<br>
</blockquote></div><br><br clear=3D"all"><div><br></div>-- <br>Harsh J
</div>

--90e6ba5bbaa31c09eb04dbbc18c0--