From de9404f02f36bf9a1100c67f41db907d494bb9ed Mon Sep 17 00:00:00 2001 From: Akira Ajisaka Date: Thu, 30 Apr 2015 20:12:32 +0900 Subject: [PATCH] HDFS-7770. Need document for storage type label of data node storage locations under dfs.data.dir. Contributed by Xiaoyu Yao. --- hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt | 3 +++ .../hadoop-hdfs/src/main/resources/hdfs-default.xml | 7 +++++-- .../hadoop-hdfs/src/site/markdown/ArchivalStorage.md | 8 ++++++++ 3 files changed, 16 insertions(+), 2 deletions(-) diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt index c538b78df9..e092dc8f37 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt +++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt @@ -603,6 +603,9 @@ Release 2.7.1 - UNRELEASED HDFS-8204. Mover/Balancer should not schedule two replicas to the same datanode. (Walter Su via szetszwo) + HDFS-7770. Need document for storage type label of data node storage + locations under dfs.data.dir. (Xiaoyu Yao via aajisaka) + OPTIMIZATIONS BUG FIXES diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml b/hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml index 092d5aa6de..f03c0fb60d 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml +++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml @@ -430,8 +430,11 @@ Determines where on the local filesystem an DFS data node should store its blocks. If this is a comma-delimited list of directories, then data will be stored in all named - directories, typically on different devices. - Directories that do not exist are ignored. + directories, typically on different devices. The directories should be tagged + with corresponding storage types ([SSD]/[DISK]/[ARCHIVE]/[RAM_DISK]) for HDFS + storage policies. The default storage type will be DISK if the directory does + not have a storage type tagged explicitly. Directories that do not exist will + be created if local filesystem permission allows. diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/ArchivalStorage.md b/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/ArchivalStorage.md index 2038401364..d924f80e8d 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/ArchivalStorage.md +++ b/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/ArchivalStorage.md @@ -95,6 +95,14 @@ The effective storage policy can be retrieved by the "[`dfsadmin -getStoragePoli ### Configuration * **dfs.storage.policy.enabled** - for enabling/disabling the storage policy feature. The default value is `true`. +* **dfs.datanode.data.dir** - on each data node, the comma-separated storage locations should be tagged with their storage types. This allows storage policies to place the blocks on different storage types according to policy. For example: + + 1. A datanode storage location /grid/dn/disk0 on DISK should be configured with `[DISK]file:///grid/dn/disk0` + 2. A datanode storage location /grid/dn/ssd0 on SSD can should configured with `[SSD]file:///grid/dn/ssd0` + 3. A datanode storage location /grid/dn/archive0 on ARCHIVE should be configured with `[ARCHIVE]file:///grid/dn/archive0` + 4. A datanode storage location /grid/dn/ram0 on RAM_DISK should be configured with `[RAM_DISK]file:///grid/dn/ram0` + + The default storage type of a datanode storage location will be DISK if it does not have a storage type tagged explicitly. Mover - A New Data Migration Tool ---------------------------------