[
https://issues.apache.org/jira/browse/HDFS-970?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12866079#action_12866079
]
dhruba borthakur commented on HDFS-970:
---------------------------------------
+1 code looks good. we should get this into 0.21 as well.
> FSImage writing should always fsync before close
> ------------------------------------------------
>
> Key: HDFS-970
> URL: https://issues.apache.org/jira/browse/HDFS-970
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: name-node
> Affects Versions: 0.20.1, 0.21.0, 0.22.0
> Reporter: Todd Lipcon
> Assignee: Todd Lipcon
> Priority: Critical
> Attachments: hdfs-970.txt
>
>
> Without an fsync, it's common that filesystems will delay the writing of
> metadata to the journal until all of the data blocks have been flushed. If
> the system crashes while the dirty pages haven't been flushed, the file is
> left in an indeterminate state. In some FSs (eg ext4) this will result in a
> 0-length file. In others (eg XFS) it will result in the correct length but
> any number of data blocks getting zeroed. Calling FileChannel.force before
> closing the FSImage prevents this issue.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
