[
https://issues.apache.org/jira/browse/HDFS-1312?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13002437#comment-13002437
]
Wang Xu commented on HDFS-1312:
-------------------------------
Hi Allen,
For the cluster monitoring issue, we could not expect an integrated monitoring
substitute the external monitoring system. Thus, we need to make clear what
information gathering requirements should be considered inside hdfs.
And the "lock" I mentions is to stop write new blocks into the volume, which is
the simplest way to migrate blocks. And I do think the depth is matter, from my
understanding, the deeper the dir is, the more io will be wasted to reach the
block.
> Re-balance disks within a Datanode
> ----------------------------------
>
> Key: HDFS-1312
> URL: https://issues.apache.org/jira/browse/HDFS-1312
> Project: Hadoop HDFS
> Issue Type: New Feature
> Components: data-node
> Reporter: Travis Crawford
>
> Filing this issue in response to ``full disk woes`` on hdfs-user.
> Datanodes fill their storage directories unevenly, leading to situations
> where certain disks are full while others are significantly less used. Users
> at many different sites have experienced this issue, and HDFS administrators
> are taking steps like:
> - Manually rebalancing blocks in storage directories
> - Decomissioning nodes & later readding them
> There's a tradeoff between making use of all available spindles, and filling
> disks at the sameish rate. Possible solutions include:
> - Weighting less-used disks heavier when placing new blocks on the datanode.
> In write-heavy environments this will still make use of all spindles,
> equalizing disk use over time.
> - Rebalancing blocks locally. This would help equalize disk use as disks are
> added/replaced in older cluster nodes.
> Datanodes should actively manage their local disk so operator intervention is
> not needed.
--
This message is automatically generated by JIRA.
-
For more information on JIRA, see: http://www.atlassian.com/software/jira
