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From Nguyen Kien Trung <trung....@gmail.com>
Subject Re: Safe mode is ON
Date Wed, 11 Jul 2007 03:29:53 GMT
Kool, i'm able to turn it off now.

Many thanks to you, Konstantin

Konstantin Shvachko wrote:
> You can always manually leave safe mode.
> bin/hadoop dfsadmin -safemode leave
> And then set replication to whatever or even remove unwanted files 
> that have bad blocks.
>
>
> Nguyen Kien Trung wrote:
>
>> Thanks Konstantin. I understand now
>>
>> " At startup the name node accepts data node reports collecting 
>> information about block locations. In order to leave safe mode it 
>> needs to collect a configurable percentage called threshold of 
>> blocks, which satisfy the minimal replication condition. The minimal 
>> replication condition is that each block must have at least 
>> dfs.replication.min replicas. When the threshold is reached the name 
>> node extends safe mode for a configurable amount of time to let the 
>> remaining data nodes to check in before it will start replicating 
>> missing blocks. Then the name node leaves safe mode."
>>
>> I realized that lots of blocks are missing their replicas. And that 
>> turns into the situation of SAFE mode.
>> Does it make sense to allow the command ./hadoop dfs -setrep to work 
>> even the name node is in safe mode? Otherwise the name node is idle 
>> forever
>>
>> Konstantin Shvachko wrote:
>>
>>> You can run "hadoop fsck / " to see how many blocks are missing on 
>>> your cluster.
>>> See definition of safe mode here.
>>> http://lucene.apache.org/hadoop/api/org/apache/hadoop/dfs/NameNode.html#setSafeMode(org.apache.hadoop.dfs.FSConstants.SafeModeAction)

>>>
>>>
>>> --Konstantin
>>>
>>> erolagnab wrote:
>>>
>>>> Hi all,
>>>>
>>>> Just wondering what is the reason causing NameNode is on SafeMode 
>>>> forever?
>>>> I've left my machine running for 2 days and it's still on Safe Mode.
>>>>
>>>> Trung
>>>>  
>>>>
>>>
>>>
>>
>>
>
>


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