diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HDFSDiskbalancer.md b/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HDFSDiskbalancer.md index 955f179be0..d3b1ca8f2e 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HDFSDiskbalancer.md +++ b/hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HDFSDiskbalancer.md @@ -37,8 +37,7 @@ A plan is a set of statements that describe how much data should move between tw A plan is composed of multiple move steps. A move step has source disk, destination disk and number of bytes to move. A plan can be executed against an operational data node. Disk balancer should not interfere with other processes since it throttles how much data is copied -every second. Please note that disk balancer is not enabled by default on a cluster. -To enable diskbalancer `dfs.disk.balancer.enabled` must be set to `true` in hdfs-site.xml. +every second. Please note that disk balancer is enabled by default on a cluster. Commands @@ -123,7 +122,7 @@ There is a set of diskbalancer settings that can be controlled via hdfs-site.xml | Setting | Description | |:---- |:---- | -|`dfs.disk.balancer.enabled`| This parameter controls if diskbalancer is enabled for a cluster. if this is not enabled, any execute command will be rejected by the datanode.The default value is false.| +|`dfs.disk.balancer.enabled`| This parameter controls if diskbalancer is enabled for a cluster. if this is not enabled, any execute command will be rejected by the datanode.The default value is true.| |`dfs.disk.balancer.max.disk.throughputInMBperSec` | This controls the maximum disk bandwidth consumed by diskbalancer while copying data. If a value like 10MB is specified then diskbalancer on the average will only copy 10MB/S. The default value is 10MB/S.| |`dfs.disk.balancer.max.disk.errors`| sets the value of maximum number of errors we can ignore for a specific move between two disks before it is abandoned. For example, if a plan has 3 pair of disks to copy between , and the first disk set encounters more than 5 errors, then we abandon the first copy and start the second copy in the plan. The default value of max errors is set to 5.| |`dfs.disk.balancer.block.tolerance.percent`| The tolerance percent specifies when we have reached a good enough value for any copy step. For example, if you specify 10% then getting close to 10% of the target value is good enough.|