Running MR job with Acitive Directory user is failing with user not found

We have PHD 3.0.1 with Isilon 7.2.1.1 deployed in secured kerberos enabled environment...

When I run MR job as pre-existing user like "ambari-qa", it works fine..

Customer logs in to client node with AD credentials, get valid kerberos tickey, and tries to run the hdfs commands, Isilon complaints with below:

Username: 'jbeal' not found. Make sure your client's username exists on the cluster

Ran command isi auth users view --user= \\ > to ensure user does exist in AD..

I see below errors in isi_hdfs_d.log file:

016-03-15T13:40:32-04:00 <1.3> isilon-dl1-1(id1) isi_hdfs_d: Failed to get token for `1: jbeal': No such file or directory

2016-03-15T13:40:32-04:00 <1.3> isilon-dl1-1(id1) isi_hdfs_d: Could not get token for zone:user 1:jbeal

2016-03-15T13:40:32-04:00 <1.3> isilon-dl1-1(id1) isi_hdfs_d: Error creating user: Bad client name:jbeal Failed to get token for `1: jbeal': No su

ch file or directory     from _get_token_and_uid_for_name (/b/mnt/src/isilon/bin/isi_hdfs_d/auth.c:250)     from _User_new (/b/mnt/src/isilon/bin/

isi_hdfs_d/auth.c:219)     from auth_cache_fetch (/b/mnt/src/isilon/bin/isi_hdfs_d/cache.in.c:136)     from hdfs_token_for_user (/b/mnt/src/isilon

/bin/isi_hdfs_d/auth.c:482)

2016-03-15T13:40:32-04:00 <1.3> isilon-dl1-1(id1) isi_hdfs_d: fd: 63 RPC #-3 raised exception: Username: 'jbeal' not found. Make sure your client'

s username exists on the cluster     from ver2_2_parse_connection_context (/b/mnt/src/isilon/bin/isi_hdfs_d/protocol_v2_2.c:363)     from process_

out_of_band_rpc (/b/mnt/src/isilon/bin/isi_hdfs_d/protocol_v2_2.c:1008)

2016-03-15T13:40:32-04:00 <1.3> isilon-dl1-1(id1) isi_hdfs_d: Deserialize failed: Username: 'jbeal' not found. Make sure your client's username ex

ists on the cluster     from ver2_2_parse_connection_context (/b/mnt/src/isilon/bin/isi_hdfs_d/protocol_v2_2.c:363)     from process_out_of_band_r

pc (/b/mnt/src/isilon/bin/isi_hdfs_d/protocol_v2_2.c:1008)     from process_one_rpc (/b/mnt/src/isilon/bin/isi_hdfs_d/protocol_v2_2.c:1168)     fr

om protocol_ver2_2_parse_rpc (/b/mnt/src/isilon/bin/isi_hdfs_d/protocol_v2_2.c:119

My understanding was user doesn't need to be created manually on Isilon side if it already exists in AD..

But apparently that's not working for me..

Any ideas?