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title How do I force disable HDFS safe mode in HDInsight cluster? | Microsoft Docs
description Use the HDFS FAQ for answers to common questions on HDFS on Azure HDInsight platform.
keywords Azure HDInsight, HDFS, FAQ, troubleshooting guide, common problems, force disable, safe mode
services Azure HDInsight
documentationcenter na
author arijitt
manager
editor
ms.assetid A8FAEEE5-87B1-4B5D-A565-69012B4AC4EA
ms.service multiple
ms.workload na
ms.tgt_pltfrm na
ms.devlang na
ms.topic article
ms.date 04/05/2017
ms.author arijitt

How do I force disable HDFS safe mode in HDInsight cluster?

Issue:

Local HDFS is stuck in safe mode on HDInsight cluster.

Detailed Description:

Fail to run simple HDFS command as follows:

hdfs dfs -D "fs.default.name=hdfs://mycluster/" -mkdir /temp

The error encountered trying to run the above command is as follows:

hdiuser@hn0-spark2:~$ hdfs dfs -D "fs.default.name=hdfs://mycluster/" -mkdir /temp
17/04/05 16:20:52 WARN retry.RetryInvocationHandler: Exception while invoking ClientNamenodeProtocolTranslatorPB.mkdirs over hn0-spark2.2oyzcdm4sfjuzjmj5dnmvscjpg.dx.internal.cloudapp.net/10.0.0.22:8020. Not retrying because try once and fail.
org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.hdfs.server.namenode.SafeModeException): Cannot create directory /temp. Name node is in safe mode.
It was turned on manually. Use "hdfs dfsadmin -safemode leave" to turn safe mode off.
        at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkNameNodeSafeMode(FSNamesystem.java:1359)
        at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.mkdirs(FSNamesystem.java:4010)
        at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.mkdirs(NameNodeRpcServer.java:1102)
        at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.mkdirs(ClientNamenodeProtocolServerSideTranslatorPB.java:630)
        at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)
        at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:640)
        at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:982)
        at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2313)
        at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2309)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAs(Subject.java:422)
        at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1724)
        at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2307)
        at org.apache.hadoop.ipc.Client.getRpcResponse(Client.java:1552)
        at org.apache.hadoop.ipc.Client.call(Client.java:1496)
        at org.apache.hadoop.ipc.Client.call(Client.java:1396)
        at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:233)
        at com.sun.proxy.$Proxy10.mkdirs(Unknown Source)
        at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.mkdirs(ClientNamenodeProtocolTranslatorPB.java:603)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:278)
        at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:194)
        at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:176)
        at com.sun.proxy.$Proxy11.mkdirs(Unknown Source)
        at org.apache.hadoop.hdfs.DFSClient.primitiveMkdir(DFSClient.java:3061)
        at org.apache.hadoop.hdfs.DFSClient.mkdirs(DFSClient.java:3031)
        at org.apache.hadoop.hdfs.DistributedFileSystem$24.doCall(DistributedFileSystem.java:1162)
        at org.apache.hadoop.hdfs.DistributedFileSystem$24.doCall(DistributedFileSystem.java:1158)
        at org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81)
        at org.apache.hadoop.hdfs.DistributedFileSystem.mkdirsInternal(DistributedFileSystem.java:1158)
        at org.apache.hadoop.hdfs.DistributedFileSystem.mkdirs(DistributedFileSystem.java:1150)
        at org.apache.hadoop.fs.FileSystem.mkdirs(FileSystem.java:1898)
        at org.apache.hadoop.fs.shell.Mkdir.processNonexistentPath(Mkdir.java:76)
        at org.apache.hadoop.fs.shell.Command.processArgument(Command.java:273)
        at org.apache.hadoop.fs.shell.Command.processArguments(Command.java:255)
        at org.apache.hadoop.fs.shell.FsCommand.processRawArguments(FsCommand.java:119)
        at org.apache.hadoop.fs.shell.Command.run(Command.java:165)
        at org.apache.hadoop.fs.FsShell.run(FsShell.java:297)
        at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:76)
        at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:90)
        at org.apache.hadoop.fs.FsShell.main(FsShell.java:350)
mkdir: Cannot create directory /temp. Name node is in safe mode.

Probable Cause:

HDInsight cluster has been scaled down to very few nodes below or close to HDFS replication factor.

Resolution Steps:

  1. Report on the status of HDFS on the HDInsight cluster with the following commands:
hdfs dfsadmin -D "fs.default.name=hdfs://mycluster/" -report
hdiuser@hn0-spark2:~$ hdfs dfsadmin -D "fs.default.name=hdfs://mycluster/" -report
Safe mode is ON
Configured Capacity: 3372381241344 (3.07 TB)
Present Capacity: 3138625077248 (2.85 TB)
DFS Remaining: 3102710317056 (2.82 TB)
DFS Used: 35914760192 (33.45 GB)
DFS Used%: 1.14%
Under replicated blocks: 0
Blocks with corrupt replicas: 0
Missing blocks: 0
Missing blocks (with replication factor 1): 0

-------------------------------------------------
Live datanodes (8):

Name: 10.0.0.17:30010 (10.0.0.17)
Hostname: 10.0.0.17
Decommission Status : Normal
Configured Capacity: 421547655168 (392.60 GB)
DFS Used: 5288128512 (4.92 GB)
Non DFS Used: 29087272960 (27.09 GB)
DFS Remaining: 387172253696 (360.58 GB)
DFS Used%: 1.25%
DFS Remaining%: 91.85%
Configured Cache Capacity: 0 (0 B)
Cache Used: 0 (0 B)
Cache Remaining: 0 (0 B)
Cache Used%: 100.00%
Cache Remaining%: 0.00%
Xceivers: 2
Last contact: Wed Apr 05 16:22:00 UTC 2017
...
  1. Check on the integrity of HDFS on the HDInsight cluster with the following commands:
hdiuser@hn0-spark2:~$ hdfs fsck -D "fs.default.name=hdfs://mycluster/" /
Connecting to namenode via http://hn0-spark2.2oyzcdm4sfjuzjmj5dnmvscjpg.dx.internal.cloudapp.net:30070/fsck?ugi=hdiuser&path=%2F
FSCK started by hdiuser (auth:SIMPLE) from /10.0.0.22 for path / at Wed Apr 05 16:40:28 UTC 2017
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..................Status: HEALTHY
 Total size:    9330539472 B
 Total dirs:    37
 Total files:   2618
 Total symlinks:                0 (Files currently being written: 2)
 Total blocks (validated):      2535 (avg. block size 3680686 B)
 Minimally replicated blocks:   2535 (100.0 %)
 Over-replicated blocks:        0 (0.0 %)
 Under-replicated blocks:       0 (0.0 %)
 Mis-replicated blocks:         0 (0.0 %)
 Default replication factor:    3
 Average block replication:     3.0
 Corrupt blocks:                0
 Missing replicas:              0 (0.0 %)
 Number of data-nodes:          8
 Number of racks:               1
FSCK ended at Wed Apr 05 16:40:28 UTC 2017 in 187 milliseconds


The filesystem under path '/' is HEALTHY
  1. If determined there are no missing, corrupt or under replicated blocks or those blocks can be ignored run the following command to take the name node out of safe mode:
hdfs dfsadmin -D "fs.default.name=hdfs://mycluster/" -safemode leave