I assume you have a SmartConnect zone set up on a pool that is tied to your zone1 access zone. And I would expect that you have configured your Hadoop cluster to connect to that SmartConnect zone. If the Hadoop cluster is for some reason connecting through the system zone this error would be expected since the user account likely doesn't exist in that zone.  Alternatively, you could increase auth and/or hdfs service logging to try to find out how the Isilon cluster is interpreting the incoming request. One of those should give details about the zone where the request was received, but may do it by zone ID which can be found with isi zone zones list -v.    
I'm deploying the 8.0.0.5 Simulator for HDP 2.5.3.0 (Ambari 2.5.2.0) and had trouble when starting YARN. The installation from Ambari went fine and HDFS service was green.  [IMAGE]  Below is the log in Ambari  stderr:   /var/lib/ambari-agent/data/errors-53.txt   Traceback (most recent call last):   File "/var/lib/ambari-agent/cache/common-services/YARN/2.1.0.2.0/package/scripts/application_timeline_server.py", line 94, in 
       ApplicationTimelineServer().execute()   File "/usr/lib/python2.6/site-packages/resource_management/libraries/script/script.py", line 329, in execute     method(env)   File "/var/lib/ambari-agent/cache/common-services/YARN/2.1.0.2.0/package/scripts/application_timeline_server.py", line 44, in start     self.configure(env) # FOR SECURITY   File "/usr/lib/python2.6/site-packages/resource_management/libraries/script/script.py", line 119, in locking_configure     original_configure(obj, *args, **kw)   File "/var/lib/ambari-agent/cache/common-services/YARN/2.1.0.2.0/package/scripts/application_timeline_server.py", line 55, in configure     yarn(name='apptimelineserver')   File "/usr/lib/python2.6/site-packages/ambari_commons/os_family_impl.py", line 89, in thunk     return fn(*args, **kwargs)   File "/var/lib/ambari-agent/cache/common-services/YARN/2.1.0.2.0/package/scripts/yarn.py", line 356, in yarn     mode=0755   File "/usr/lib/python2.6/site-packages/resource_management/core/base.py", line 166, in __init__     self.env.run()   File "/usr/lib/python2.6/site-packages/resource_management/core/environment.py", line 160, in run     self.run_action(resource, action)   File "/usr/lib/python2.6/site-packages/resource_management/core/environment.py", line 124, in run_action     provider_action()   File "/usr/lib/python2.6/site-packages/resource_management/libraries/providers/hdfs_resource.py", line 604, in action_create_on_execute     self.action_delayed("create")   File "/usr/lib/python2.6/site-packages/resource_management/libraries/providers/hdfs_resource.py", line 601, in action_delayed     self.get_hdfs_resource_executor().action_delayed(action_name, self)   File "/usr/lib/python2.6/site-packages/resource_management/libraries/providers/hdfs_resource.py", line 328, in action_delayed     self._assert_valid()   File "/usr/lib/python2.6/site-packages/resource_management/libraries/providers/hdfs_resource.py", line 287, in _assert_valid     self.target_status = self._get_file_status(target)   File "/usr/lib/python2.6/site-packages/resource_management/libraries/providers/hdfs_resource.py", line 430, in _get_file_status     list_status = self.util.run_command(target, 'GETFILESTATUS', method='GET', ignore_status_codes=['404'], assertable_result=False)   File "/usr/lib/python2.6/site-packages/resource_management/libraries/providers/hdfs_resource.py", line 177, in run_command     return self._run_command(*args, **kwargs)   File "/usr/lib/python2.6/site-packages/resource_management/libraries/providers/hdfs_resource.py", line 248, in _run_command     raise WebHDFSCallException(err_msg, result_dict) resource_management.libraries.providers.hdfs_resource.WebHDFSCallException: Execution of 'curl -sS -L -w '%{http_code}' -X GET '[URL] returned status_code=401.  {
     "RemoteException": {
       "exception": "AuthorizationException",      "javaClassName": "org.apache.hadoop.security.authorize.AuthorizationException",      "message": "Username: 'hdfs' not found. Make sure your client's username exists on the cluster"   } }   stdout:   /var/lib/ambari-agent/data/output-53.txt   2017-10-25 15:23:49,100 - Stack Feature Version Info: Cluster Stack=2.5, Cluster Current Version=None, Command Stack=None, Command Version=2.5.3.0-37 -> 2.5.3.0-37 2017-10-25 15:23:49,111 - Using hadoop conf dir: /usr/hdp/current/hadoop-client/conf 2017-10-25 15:23:49,561 - Stack Feature Version Info: Cluster Stack=2.5, Cluster Current Version=None, Command Stack=None, Command Version=2.5.3.0-37 -> 2.5.3.0-37 2017-10-25 15:23:49,562 - Using hadoop conf dir: /usr/hdp/current/hadoop-client/conf User Group mapping (user_group) is missing in the hostLevelParams 2017-10-25 15:23:49,569 - Group['hadoop'] {} 2017-10-25 15:23:49,576 - Group['users'] {} 2017-10-25 15:23:49,577 - File['/var/lib/ambari-agent/tmp/changeUid.sh'] {'content': StaticFile('changeToSecureUid.sh'), 'mode': 0555} 2017-10-25 15:23:49,587 - call['/var/lib/ambari-agent/tmp/changeUid.sh zookeeper'] {} 2017-10-25 15:23:49,631 - call returned (0, '512') 2017-10-25 15:23:49,632 - User['zookeeper'] {'gid': 'hadoop', 'fetch_nonlocal_groups': True, 'groups': ['hadoop'], 'uid': 512} 2017-10-25 15:23:49,633 - File['/var/lib/ambari-agent/tmp/changeUid.sh'] {'content': StaticFile('changeToSecureUid.sh'), 'mode': 0555} 2017-10-25 15:23:49,634 - call['/var/lib/ambari-agent/tmp/changeUid.sh ams'] {} 2017-10-25 15:23:49,670 - call returned (0, '524') 2017-10-25 15:23:49,670 - User['ams'] {'gid': 'hadoop', 'fetch_nonlocal_groups': True, 'groups': ['hadoop'], 'uid': 524} 2017-10-25 15:23:49,672 - User['ambari-qa'] {'gid': 'hadoop', 'fetch_nonlocal_groups': True, 'groups': ['users'], 'uid': None} 2017-10-25 15:23:49,673 - File['/var/lib/ambari-agent/tmp/changeUid.sh'] {'content': StaticFile('changeToSecureUid.sh'), 'mode': 0555} 2017-10-25 15:23:49,676 - call['/var/lib/ambari-agent/tmp/changeUid.sh hdfs'] {} 2017-10-25 15:23:49,708 - call returned (0, '501') 2017-10-25 15:23:49,709 - User['hdfs'] {'gid': 'hadoop', 'fetch_nonlocal_groups': True, 'groups': ['hadoop'], 'uid': 501} 2017-10-25 15:23:49,711 - File['/var/lib/ambari-agent/tmp/changeUid.sh'] {'content': StaticFile('changeToSecureUid.sh'), 'mode': 0555} 2017-10-25 15:23:49,713 - call['/var/lib/ambari-agent/tmp/changeUid.sh yarn'] {} 2017-10-25 15:23:49,743 - call returned (0, '503') 2017-10-25 15:23:49,744 - User['yarn'] {'gid': 'hadoop', 'fetch_nonlocal_groups': True, 'groups': ['hadoop'], 'uid': 503} 2017-10-25 15:23:49,745 - File['/var/lib/ambari-agent/tmp/changeUid.sh'] {'content': StaticFile('changeToSecureUid.sh'), 'mode': 0555} 2017-10-25 15:23:49,746 - call['/var/lib/ambari-agent/tmp/changeUid.sh mapred'] {} 2017-10-25 15:23:49,776 - call returned (0, '502') 2017-10-25 15:23:49,776 - User['mapred'] {'gid': 'hadoop', 'fetch_nonlocal_groups': True, 'groups': ['hadoop'], 'uid': 502} 2017-10-25 15:23:49,778 - File['/var/lib/ambari-agent/tmp/changeUid.sh'] {'content': StaticFile('changeToSecureUid.sh'), 'mode': 0555} 2017-10-25 15:23:49,781 - Execute['/var/lib/ambari-agent/tmp/changeUid.sh ambari-qa /tmp/hadoop-ambari-qa,/tmp/hsperfdata_ambari-qa,/home/ambari-qa,/tmp/ambari-qa,/tmp/sqoop-ambari-qa 0'] {'not_if': '(test $(id -u ambari-qa) -gt 1000) || (false)'} 2017-10-25 15:23:49,805 - Skipping Execute['/var/lib/ambari-agent/tmp/changeUid.sh ambari-qa /tmp/hadoop-ambari-qa,/tmp/hsperfdata_ambari-qa,/home/ambari-qa,/tmp/ambari-qa,/tmp/sqoop-ambari-qa 0'] due to not_if 2017-10-25 15:23:49,806 - Group['hdfs'] {} 2017-10-25 15:23:49,806 - User['hdfs'] {'fetch_nonlocal_groups': True, 'groups': ['hadoop', 'hdfs']} 2017-10-25 15:23:49,807 - FS Type:  2017-10-25 15:23:49,807 - Directory['/etc/hadoop'] {'mode': 0755} 2017-10-25 15:23:49,855 - File['/usr/hdp/current/hadoop-client/conf/hadoop-env.sh'] {'content': InlineTemplate(...), 'owner': 'hdfs', 'group': 'hadoop'} 2017-10-25 15:23:49,855 - Directory['/var/lib/ambari-agent/tmp/hadoop_java_io_tmpdir'] {'owner': 'hdfs', 'group': 'hadoop', 'mode': 01777} 2017-10-25 15:23:49,900 - Execute[('setenforce', '0')] {'not_if': '(! which getenforce ) || (which getenforce && getenforce | grep -q Disabled)', 'sudo': True, 'only_if': 'test -f /selinux/enforce'} 2017-10-25 15:23:50,014 - Directory['/var/log/hadoop'] {'owner': 'root', 'create_parents': True, 'group': 'hadoop', 'mode': 0775, 'cd_access': 'a'} 2017-10-25 15:23:50,016 - Directory['/var/run/hadoop'] {'owner': 'root', 'create_parents': True, 'group': 'root', 'cd_access': 'a'} 2017-10-25 15:23:50,016 - Directory['/tmp/hadoop-hdfs'] {'owner': 'hdfs', 'create_parents': True, 'cd_access': 'a'} 2017-10-25 15:23:50,039 - File['/usr/hdp/current/hadoop-client/conf/commons-logging.properties'] {'content': Template('commons-logging.properties.j2'), 'owner': 'hdfs'} 2017-10-25 15:23:50,052 - File['/usr/hdp/current/hadoop-client/conf/health_check'] {'content': Template('health_check.j2'), 'owner': 'hdfs'} 2017-10-25 15:23:50,084 - File['/usr/hdp/current/hadoop-client/conf/log4j.properties'] {'content': InlineTemplate(...), 'owner': 'hdfs', 'group': 'hadoop', 'mode': 0644} 2017-10-25 15:23:50,130 - File['/usr/hdp/current/hadoop-client/conf/hadoop-metrics2.properties'] {'content': Template('hadoop-metrics2.properties.j2'), 'owner': 'hdfs', 'group': 'hadoop'} 2017-10-25 15:23:50,131 - File['/usr/hdp/current/hadoop-client/conf/task-log4j.properties'] {'content': StaticFile('task-log4j.properties'), 'mode': 0755} 2017-10-25 15:23:50,132 - File['/usr/hdp/current/hadoop-client/conf/configuration.xsl'] {'owner': 'hdfs', 'group': 'hadoop'} 2017-10-25 15:23:50,156 - File['/etc/hadoop/conf/topology_mappings.data'] {'owner': 'hdfs', 'content': Template('topology_mappings.data.j2'), 'only_if': 'test -d /etc/hadoop/conf', 'group': 'hadoop', 'mode': 0644} 2017-10-25 15:23:50,172 - File['/etc/hadoop/conf/topology_script.py'] {'content': StaticFile('topology_script.py'), 'only_if': 'test -d /etc/hadoop/conf', 'mode': 0755} 2017-10-25 15:23:50,716 - Using hadoop conf dir: /usr/hdp/current/hadoop-client/conf 2017-10-25 15:23:50,717 - Stack Feature Version Info: Cluster Stack=2.5, Cluster Current Version=None, Command Stack=None, Command Version=2.5.3.0-37 -> 2.5.3.0-37 2017-10-25 15:23:50,720 - call['ambari-python-wrap /usr/bin/hdp-select status hadoop-yarn-resourcemanager'] {'timeout': 20} 2017-10-25 15:23:50,784 - call returned (0, 'hadoop-yarn-resourcemanager - 2.5.3.0-37') 2017-10-25 15:23:50,789 - Using hadoop conf dir: /usr/hdp/current/hadoop-client/conf 2017-10-25 15:23:50,816 - Directory['/var/log/hadoop-yarn/nodemanager/recovery-state'] {'owner': 'yarn', 'group': 'hadoop', 'create_parents': True, 'mode': 0755, 'cd_access': 'a'} 2017-10-25 15:23:50,824 - Directory['/var/run/hadoop-yarn'] {'owner': 'yarn', 'create_parents': True, 'group': 'hadoop', 'cd_access': 'a'} 2017-10-25 15:23:50,825 - Directory['/var/run/hadoop-yarn/yarn'] {'owner': 'yarn', 'create_parents': True, 'group': 'hadoop', 'cd_access': 'a'} 2017-10-25 15:23:50,826 - Directory['/var/log/hadoop-yarn/yarn'] {'owner': 'yarn', 'group': 'hadoop', 'create_parents': True, 'cd_access': 'a'} 2017-10-25 15:23:50,826 - Directory['/var/run/hadoop-mapreduce'] {'owner': 'mapred', 'create_parents': True, 'group': 'hadoop', 'cd_access': 'a'} 2017-10-25 15:23:50,827 - Directory['/var/run/hadoop-mapreduce/mapred'] {'owner': 'mapred', 'create_parents': True, 'group': 'hadoop', 'cd_access': 'a'} 2017-10-25 15:23:50,831 - Directory['/var/log/hadoop-mapreduce'] {'owner': 'mapred', 'create_parents': True, 'group': 'hadoop', 'cd_access': 'a'} 2017-10-25 15:23:50,834 - Directory['/var/log/hadoop-mapreduce/mapred'] {'owner': 'mapred', 'group': 'hadoop', 'create_parents': True, 'cd_access': 'a'} 2017-10-25 15:23:50,834 - Directory['/var/log/hadoop-yarn'] {'owner': 'yarn', 'group': 'hadoop', 'ignore_failures': True, 'create_parents': True, 'cd_access': 'a'} 2017-10-25 15:23:50,837 - XmlConfig['core-site.xml'] {'group': 'hadoop', 'conf_dir': '/usr/hdp/current/hadoop-client/conf', 'mode': 0644, 'configuration_attributes': {'final': {'fs.defaultFS': 'true'}}, 'owner': 'hdfs', 'configurations': ...} 2017-10-25 15:23:50,858 - Generating config: /usr/hdp/current/hadoop-client/conf/core-site.xml 2017-10-25 15:23:50,859 - File['/usr/hdp/current/hadoop-client/conf/core-site.xml'] {'owner': 'hdfs', 'content': InlineTemplate(...), 'group': 'hadoop', 'mode': 0644, 'encoding': 'UTF-8'} 2017-10-25 15:23:50,901 - XmlConfig['hdfs-site.xml'] {'group': 'hadoop', 'conf_dir': '/usr/hdp/current/hadoop-client/conf', 'mode': 0644, 'configuration_attributes': {'final': {'dfs.support.append': 'true', 'dfs.datanode.data.dir': 'true', 'dfs.namenode.http-address': 'true', 'dfs.namenode.name.dir': 'true', 'dfs.webhdfs.enabled': 'true', 'dfs.datanode.failed.volumes.tolerated': 'true'}}, 'owner': 'hdfs', 'configurations': ...} 2017-10-25 15:23:50,919 - Generating config: /usr/hdp/current/hadoop-client/conf/hdfs-site.xml 2017-10-25 15:23:50,920 - File['/usr/hdp/current/hadoop-client/conf/hdfs-site.xml'] {'owner': 'hdfs', 'content': InlineTemplate(...), 'group': 'hadoop', 'mode': 0644, 'encoding': 'UTF-8'} 2017-10-25 15:23:51,113 - XmlConfig['mapred-site.xml'] {'group': 'hadoop', 'conf_dir': '/usr/hdp/current/hadoop-client/conf', 'mode': 0644, 'configuration_attributes': {}, 'owner': 'yarn', 'configurations': ...} 2017-10-25 15:23:51,134 - Generating config: /usr/hdp/current/hadoop-client/conf/mapred-site.xml 2017-10-25 15:23:51,134 - File['/usr/hdp/current/hadoop-client/conf/mapred-site.xml'] {'owner': 'yarn', 'content': InlineTemplate(...), 'group': 'hadoop', 'mode': 0644, 'encoding': 'UTF-8'} 2017-10-25 15:23:51,220 - Changing owner for /usr/hdp/current/hadoop-client/conf/mapred-site.xml from 502 to yarn 2017-10-25 15:23:51,220 - XmlConfig['yarn-site.xml'] {'group': 'hadoop', 'conf_dir': '/usr/hdp/current/hadoop-client/conf', 'mode': 0644, 'configuration_attributes': {}, 'owner': 'yarn', 'configurations': ...} 2017-10-25 15:23:51,238 - Generating config: /usr/hdp/current/hadoop-client/conf/yarn-site.xml 2017-10-25 15:23:51,238 - File['/usr/hdp/current/hadoop-client/conf/yarn-site.xml'] {'owner': 'yarn', 'content': InlineTemplate(...), 'group': 'hadoop', 'mode': 0644, 'encoding': 'UTF-8'} 2017-10-25 15:23:51,463 - XmlConfig['capacity-scheduler.xml'] {'group': 'hadoop', 'conf_dir': '/usr/hdp/current/hadoop-client/conf', 'mode': 0644, 'configuration_attributes': {}, 'owner': 'yarn', 'configurations': ...} 2017-10-25 15:23:51,477 - Generating config: /usr/hdp/current/hadoop-client/conf/capacity-scheduler.xml 2017-10-25 15:23:51,478 - File['/usr/hdp/current/hadoop-client/conf/capacity-scheduler.xml'] {'owner': 'yarn', 'content': InlineTemplate(...), 'group': 'hadoop', 'mode': 0644, 'encoding': 'UTF-8'} 2017-10-25 15:23:51,500 - Changing owner for /usr/hdp/current/hadoop-client/conf/capacity-scheduler.xml from 501 to yarn 2017-10-25 15:23:51,501 - Directory['/hadoop/yarn/timeline'] {'owner': 'yarn', 'group': 'hadoop', 'create_parents': True, 'cd_access': 'a'} 2017-10-25 15:23:51,501 - Directory['/hadoop/yarn/timeline'] {'owner': 'yarn', 'group': 'hadoop', 'create_parents': True, 'cd_access': 'a'} 2017-10-25 15:23:51,502 - HdfsResource['/ats/done'] {'security_enabled': False, 'hadoop_bin_dir': '/usr/hdp/current/hadoop-client/bin', 'keytab': [EMPTY], 'dfs_type': '', 'default_fs': 'hdfs://zone1.demo.local:8020', 'hdfs_resource_ignore_file': '/var/lib/ambari-agent/data/.hdfs_resource_ignore', 'hdfs_site': ..., 'kinit_path_local': 'kinit', 'principal_name': [EMPTY], 'user': 'hdfs', 'change_permissions_for_parents': True, 'owner': 'yarn', 'group': 'hadoop', 'hadoop_conf_dir': '/usr/hdp/current/hadoop-client/conf', 'type': 'directory', 'action': ['create_on_execute'], 'immutable_paths': [u'/mr-history/done', u'/app-logs', u'/tmp'], 'mode': 0755} 2017-10-25 15:23:51,505 - call['ambari-sudo.sh su hdfs -l -s /bin/bash -c 'curl -sS -L -w '"'"'%{http_code}'"'"' -X GET '"'"'[URL]"'"' 1>/tmp/tmpKY8eVN 2>/tmp/tmpOto4VM''] {'logoutput': None, 'quiet': False} 2017-10-25 15:23:51,634 - call returned (0, 'su: warning: cannot change directory to /home/hdfs: No such file or directory')   Command failed after 1 tries  if I access the Ambari client to su - hdfs then hdfs dfs -ls /, I got this:  17/10/25 16:18:21 WARN retry.RetryInvocationHandler: Exception while invoking ClientNamenodeProtocolTranslatorPB.getFileInfo over null. Not retrying because try once and fail. org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.security.authorize.AuthorizationException): Username: 'hdfs' not found. Make sure your client's username exists on the cluster 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.$Proxy10.getFileInfo(Unknown Source) at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.getFileInfo(ClientNamenodeProtocolTranslatorPB.java:816) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:278) at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:194) at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:176) at com.sun.proxy.$Proxy11.getFileInfo(Unknown Source) at org.apache.hadoop.hdfs.DFSClient.getFileInfo(DFSClient.java:2158) at org.apache.hadoop.hdfs.DistributedFileSystem$25.doCall(DistributedFileSystem.java:1423) at org.apache.hadoop.hdfs.DistributedFileSystem$25.doCall(DistributedFileSystem.java:1419) at org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81) at org.apache.hadoop.hdfs.DistributedFileSystem.getFileStatus(DistributedFileSystem.java:1419) at org.apache.hadoop.fs.Globber.getFileStatus(Globber.java:57) at org.apache.hadoop.fs.Globber.glob(Globber.java:265) at org.apache.hadoop.fs.FileSystem.globStatus(FileSystem.java:1674) at org.apache.hadoop.fs.shell.PathData.expandAsGlob(PathData.java:326) at org.apache.hadoop.fs.shell.Command.expandArgument(Command.java:235) at org.apache.hadoop.fs.shell.Command.expandArguments(Command.java:218) at org.apache.hadoop.fs.shell.FsCommand.processRawArguments(FsCommand.java:103) 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) ls: Username: 'hdfs' not found. Make sure your client's username exists on the cluster  When I do  id hdfs. I got this which seems correct: uid=501(hdfs) gid=538(hadoop) groups=538(hadoop),501(hdfs)  Here is the output from Isilon as root (obviously the hdfs user does exists):  isilon1-1# isi auth users view hdfs --zone=zone1                     Name: hdfs                       DN: CN=hdfs,CN=Users,DC=ISILON1               DNS Domain: -                   Domain: ISILON1                 Provider: lsa-local-provider:zone1         Sam Account Name: hdfs                      UID: 501                      SID: S-1-5-21-837597287-2823100475-1132252091-1038                  Enabled: No                  Expired: No                   Expiry: -                   Locked: No                    Email: -                    GECOS: -            Generated GID: No            Generated UID: No            Generated UPN: Yes            Primary Group                           ID: GID:501                         Name: hdfs           Home Directory: /ifs/zone1/hdp/home/hdfs         Max Password Age: 4W         Password Expired: No          Password Expiry: 2017-11-22T21:53:46        Password Last Set: 2017-10-25T21:53:46         Password Expires: Yes                    Shell: /bin/zsh                      UPN: hdfs[NAME] User Can Change Password: Yes   When I installed, before register Isilon in Ambari, I used below content for uid and groups which seem correct also:  isilon1-1# cat zone1.passwd # use this file to add to the passwd file of your clients hdfs:x:501:501:hadoop-svc-account:/home/hdfs:/bin/bash mapred:x:502:502:hadoop-svc-account:/home/mapred:/bin/bash yarn:x:503:503:hadoop-svc-account:/home/yarn:/bin/bash hbase:x:504:504:hadoop-svc-account:/home/hbase:/bin/bash storm:x:505:505:hadoop-svc-account:/home/storm:/bin/bash falcon:x:506:506:hadoop-svc-account:/home/falcon:/bin/bash tracer:x:507:507:hadoop-svc-account:/home/tracer:/bin/bash tez:x:508:508:hadoop-svc-account:/home/tez:/bin/bash hive:x:509:509:hadoop-svc-account:/home/hive:/bin/bash hcat:x:510:510:hadoop-svc-account:/home/hcat:/bin/bash oozie:x:511:511:hadoop-svc-account:/home/oozie:/bin/bash zookeeper:x:512:512:hadoop-svc-account:/home/zookeeper:/bin/bash ambari-qa:x:513:513:hadoop-svc-account:/home/ambari-qa:/bin/bash flume:x:514:514:hadoop-svc-account:/home/flume:/bin/bash hue:x:515:515:hadoop-svc-account:/home/hue:/bin/bash accumulo:x:516:516:hadoop-svc-account:/home/accumulo:/bin/bash hadoopqa:x:517:517:hadoop-svc-account:/home/hadoopqa:/bin/bash sqoop:x:518:518:hadoop-svc-account:/home/sqoop:/bin/bash spark:x:519:519:hadoop-svc-account:/home/spark:/bin/bash mahout:x:520:520:hadoop-svc-account:/home/mahout:/bin/bash ranger:x:521:521:hadoop-svc-account:/home/ranger:/bin/bash kms:x:522:522:hadoop-svc-account:/home/kms:/bin/bash atlas:x:523:523:hadoop-svc-account:/home/atlas:/bin/bash ams:x:524:524:hadoop-svc-account:/home/ams:/bin/bash kafka:x:525:525:hadoop-svc-account:/home/kafka:/bin/bash zeppelin:x:526:526:hadoop-svc-account:/home/zeppelin:/bin/bash livy:x:527:527:hadoop-svc-account:/home/livy:/bin/bash logsearch:x:528:528:hadoop-svc-account:/home/logsearch:/bin/bash infra-solr:x:529:529:hadoop-svc-account:/home/infra-solr:/bin/bash activity_analyzer:x:530:530:hadoop-svc-account:/home/activity_analyzer:/bin/bash activity_explorer:x:531:531:hadoop-svc-account:/home/activity_explorer:/bin/bash HTTP:x:532:532:hadoop-svc-account:/home/HTTP:/bin/bash knox:x:533:533:hadoop-svc-account:/home/knox:/bin/bash ambari-server:x:534:534:hadoop-svc-account:/home/ambari-server:/bin/bash druid:x:535:535:hadoop-svc-account:/home/druid:/bin/bash anonymous:x:536:536:hadoop-svc-account:/home/anonymous:/bin/bash admin:x:537:537:hadoop-svc-account:/home/admin:/bin/bash   isilon1-1# cat zone1.group # use this file to add to the group file of your clients hdfs:x:501: mapred:x:502: yarn:x:503: hbase:x:504: storm:x:505: falcon:x:506: tracer:x:507: tez:x:508: hive:x:509: hcat:x:510: oozie:x:511: zookeeper:x:512: ambari-qa:x:513: flume:x:514: hue:x:515: accumulo:x:516: sqoop:x:518: spark:x:519: mahout:x:520: ranger:x:521: kms:x:522: atlas:x:523: ams:x:524: kafka:x:525: zeppelin:x:526: livy:x:527: logsearch:x:528: infra-solr:x:529: activity_analyzer:x:530: activity_explorer:x:531: HTTP:x:532: knox:x:533: ambari-server:x:534: druid:x:535: anonymous:x:536: admin:x:537: hadoopqa:x:517: hadoop:x:538:hdfs,mapred,yarn,hbase,storm,falcon,tracer,tez,hive,hcat,oozie,zookeeper,ambari-qa,flume,hue,accumulo,hadoopqa,sqoop,spark,mahout,ranger,kms,atlas,ams,kafka,zeppelin,livy,logsearch,infra-solr,activity_analyzer,activity_explorer,HTTP,knox,ambari-server,druid,  So frankly I am not sure what caused username hdfs (as well as all other users) to be not found.  Any idea to troubleshoot?
Isilon 8.0.0.5 Simulator Username: 'hdfs' not found with HDP 2.5.3.0