[ 
https://issues.apache.org/jira/browse/HDFS-718?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12772582#action_12772582
 ] 

dhruba borthakur commented on HDFS-718:
---------------------------------------

hi allen, koji: can somebody pl review this patch and comment on whether it is 
useful to the general hadoop community?

> configuration parameter to prevent accidental formatting of HDFS filesystem
> ---------------------------------------------------------------------------
>
>                 Key: HDFS-718
>                 URL: https://issues.apache.org/jira/browse/HDFS-718
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>          Components: name-node
>    Affects Versions: 0.22.0
>         Environment: Any
>            Reporter: Andrew Ryan
>            Assignee: Andrew Ryan
>            Priority: Minor
>         Attachments: HDFS-718.patch.txt
>
>
> Currently, any time the NameNode is not running, an HDFS filesystem will 
> accept the 'format' command, and will duly format itself. There are those of 
> us who have multi-PB HDFS filesystems who are really quite uncomfortable with 
> this behavior. There is "Y/N" confirmation in the format command, but if the 
> formatter genuinely believes themselves to be doing the right thing, the 
> filesystem will be formatted.
> This patch adds a configuration parameter to the namenode, 
> dfs.namenode.support.allowformat, which defaults to "true," the current 
> behavior: always allow formatting if the NameNode is down or some other 
> process is not holding the namenode lock. But if 
> dfs.namenode.support.allowformat is set to "false," the NameNode will not 
> allow itself to be formatted until this config parameter is changed to "true".
> The general idea is that for production HDFS filesystems, the user would 
> format the HDFS once, then set dfs.namenode.support.allowformat to "false" 
> for all time.
> The attached patch was generated against trunk and +1's on my test machine. 
> We have a 0.20 version that we are using in our cluster as well.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.

Reply via email to