[HDFS-7770] Need document for storage type label of data node storage locations under dfs.datanode.data.dir

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.6.0
• Fix Version/s: 2.8.0, 2.7.1, 3.0.0-alpha1
• Component/s: documentation
• Target Version/s: 2.7.1
• Hadoop Flags: Reviewed
• Assignee: Xiaoyu Yao Assign to me
• Reporter: Xiaoyu Yao
• Created: 10/Feb/15 20:19
• Updated: 30/Aug/16 01:39
• Resolved: 30/Apr/15 11:15

Description

HDFS-2832 enables support for heterogeneous storages in HDFS, which allows DN as a collection of storages with different types. However, I can't find document on how to label different storage types from the following two documents. I found the information from the design spec. It will be good we document this for admins and users to use the related Archival storage and storage policy features.

http://hadoop.apache.org/docs/r2.6.0/hadoop-project-dist/hadoop-hdfs/ArchivalStorage.html

http://hadoop.apache.org/docs/r2.6.0/hadoop-project-dist/hadoop-hdfs/hdfs-default.xml

This JIRA is opened to add document for the new storage type labels.

1. Add an example under ArchivalStorage.html#Configuration section:

  <property>
    <name>dfs.datanode.data.dir</name>
    <value>[DISK]file:///hddata/dn/disk0,  [SSD]file:///hddata/dn/ssd0,[ARCHIVE]file:///hddata/dn/archive0</value>
  </property>

2. Add a short description of [DISK/SSD/ARCHIVE/RAM_DISK] options in hdfs-default.xml#dfs.data.dir and document DISK as storage type if no storage type is labeled in the data node storage location configuration.

Issue Links

• is duplicated by: HDFS-8279 Document how to specify storage types
• relates to: HDFS-5000 DataNode configuration should allow specifying storage type