[ 
https://issues.apache.org/jira/browse/HADOOP-13738?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15593080#comment-15593080
 ] 

Kihwal Lee commented on HADOOP-13738:
-------------------------------------

bq. I don't remember seeing this one yet. Do you have a theory on what causes 
it?
I think the cause is mainly latent sector error.  As drives getting larger and 
larger, these can go unnoticed for long time. Even with the "data_err=abort" 
mount option, the delayed block allocation error detected at EXT4 level doesn't 
normally cause the journal to be aborted (then become read-only), let alone 
reacting to read errors. The SMART data (e.g. remapping count) sometimes 
correlates to such read errors, but not all the time. I think there is large 
variance with manufacturer/model.

> DiskChecker should perform some disk IO
> ---------------------------------------
>
>                 Key: HADOOP-13738
>                 URL: https://issues.apache.org/jira/browse/HADOOP-13738
>             Project: Hadoop Common
>          Issue Type: Improvement
>            Reporter: Arpit Agarwal
>            Assignee: Arpit Agarwal
>         Attachments: HADOOP-13738.01.patch
>
>
> DiskChecker can fail to detect total disk/controller failures indefinitely. 
> We have seen this in real clusters. DiskChecker performs simple 
> permissions-based checks on directories which do not guarantee that any disk 
> IO will be attempted.
> A simple improvement is to write some data and flush it to the disk.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

---------------------------------------------------------------------
To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: common-issues-h...@hadoop.apache.org

Reply via email to