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Hi

I have been facing some problems in Hadoop. I find the Namennode to be in safe mode?? May I knw why namenode is in safe mode and what happens when it is in safe mode?

Thanks in advance
Preethi.C


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  • Ned Rockson at Oct 17, 2007 at 6:04 am
    I think it's in safe mode for a short time after startup to check the
    integrity of the file system.
    On 10/16/07, Preethi Chockalingam wrote:
    Hi

    I have been facing some problems in Hadoop. I find the Namennode to be in safe mode?? May I knw why namenode is in safe mode and what happens when it is in safe mode?

    Thanks in advance
    Preethi.C


    Download prohibited? No problem. CHAT from any browser, without download. Go to http://in.messenger.yahoo.com/webmessengerpromo.php/
  • Cpreethi at Oct 17, 2007 at 6:17 am
    Hi

    It has been in safe mode all time. I am not bale to execute jobs too. I find
    some error sayin canot delete file. Namenode is in safemode.

    Thanks,
    Preethi.C


    Ned Rockson wrote:
    I think it's in safe mode for a short time after startup to check the
    integrity of the file system.
    On 10/16/07, Preethi Chockalingam wrote:
    Hi

    I have been facing some problems in Hadoop. I find the Namennode to be in
    safe mode?? May I knw why namenode is in safe mode and what happens when
    it is in safe mode?

    Thanks in advance
    Preethi.C


    Download prohibited? No problem. CHAT from any browser, without
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    View this message in context: http://www.nabble.com/Namenode-Safe-Mode--tf4638271.html#a13247735
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  • Lance Amundsen at Oct 17, 2007 at 6:32 am
    bin/hadoop dfs -safemode leave

    or close to that (check the syntax) has gotten me out of this state in the
    past





    cpreethi
    <cpreethi86@yahoo
    .co.in> To
    hadoop-user@lucene.apache.org
    10/16/2007 11:17 cc
    PM
    Subject
    Re: Namenode Safe Mode?
    Please respond to
    hadoop-user@lucen
    e.apache.org








    Hi

    It has been in safe mode all time. I am not bale to execute jobs too. I
    find
    some error sayin canot delete file. Namenode is in safemode.

    Thanks,
    Preethi.C


    Ned Rockson wrote:
    I think it's in safe mode for a short time after startup to check the
    integrity of the file system.
    On 10/16/07, Preethi Chockalingam wrote:
    Hi

    I have been facing some problems in Hadoop. I find the Namennode to be
    in
    safe mode?? May I knw why namenode is in safe mode and what happens when
    it is in safe mode?

    Thanks in advance
    Preethi.C


    Download prohibited? No problem. CHAT from any browser, without
    download. Go to http://in.messenger.yahoo.com/webmessengerpromo.php/
    --
    View this message in context:
    http://www.nabble.com/Namenode-Safe-Mode--tf4638271.html#a13247735
    Sent from the Hadoop Users mailing list archive at Nabble.com.
  • Owen O'Malley at Oct 17, 2007 at 1:29 pm

    On Oct 16, 2007, at 11:17 PM, cpreethi wrote:

    It has been in safe mode all time. I am not bale to execute jobs
    too. I find
    some error sayin canot delete file. Namenode is in safemode.
    Safe mode is the original state of the NameNode until it has a large
    enough collection of DataNodes have reported in to have at least 1
    copy of at least X% of the blocks. (The default X is 99.9%). I
    recommend changing it to 100%. You can force the NameNode to leave
    safe mode manually via "bin/hadoop dfsadmin -safemode leave". In safe
    mode, the NameNode lets client do read-only operations but not write
    operations (including replication decisions).

    -- Owen
  • Konstantin Shvachko at Oct 17, 2007 at 6:08 pm
    to have at least 1 copy of at least X% of the blocks
    Not 1, but dfs.replication.min, which by default is 1.
    See also
    http://wiki.apache.org/lucene-hadoop/FAQ#12
    http://lucene.apache.org/hadoop/api/org/apache/hadoop/dfs/NameNode.html#setSafeMode(org.apache.hadoop.dfs.FSConstants.SafeModeAction)

    --Konstantin

    Owen O'Malley wrote:
    On Oct 16, 2007, at 11:17 PM, cpreethi wrote:

    It has been in safe mode all time. I am not bale to execute jobs
    too. I find
    some error sayin canot delete file. Namenode is in safemode.

    Safe mode is the original state of the NameNode until it has a large
    enough collection of DataNodes have reported in to have at least 1
    copy of at least X% of the blocks. (The default X is 99.9%). I
    recommend changing it to 100%. You can force the NameNode to leave
    safe mode manually via "bin/hadoop dfsadmin -safemode leave". In safe
    mode, the NameNode lets client do read-only operations but not write
    operations (including replication decisions).

    -- Owen
  • Ted Dunning at Oct 17, 2007 at 4:52 pm
    I have found it very helpful to use

    hadoop fsck /

    In these situations.

    If the files that are problematic are not important for you, then you can
    exit safe mode explicitly and just delete these files. That will give you a
    clean file system.

    Examples of files that might be OK to delete include left-over files from
    aborted map-reduce jobs or files that you can just re-import into the HDFS
    from other storage.
    On 10/16/07 11:17 PM, "cpreethi" wrote:


    Hi

    It has been in safe mode all time. I am not bale to execute jobs too. I find
    some error sayin canot delete file. Namenode is in safemode.

    Thanks,
    Preethi.C


    Ned Rockson wrote:
    I think it's in safe mode for a short time after startup to check the
    integrity of the file system.
    On 10/16/07, Preethi Chockalingam wrote:
    Hi

    I have been facing some problems in Hadoop. I find the Namennode to be in
    safe mode?? May I knw why namenode is in safe mode and what happens when
    it is in safe mode?

    Thanks in advance
    Preethi.C


    Download prohibited? No problem. CHAT from any browser, without
    download. Go to http://in.messenger.yahoo.com/webmessengerpromo.php/

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postedOct 17, '07 at 5:06a
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