See this comment for the complete description of what is happening here.
Users from non-default krb5 domain can't use hadoop-fuse.
There are 2 Realms with kdc.
-one realm is for human users (USERS.COM.US)
-the other is for service principals. (SERVICE.COM.US)
Cross realm trust is setup.
In krb5.conf the default domain is set to SERVICE.COM.US
Users within USERS.COM.US Realm are not able to put any files to Fuse mounted location
The client shows:
cp: cannot create regular file ‘/hdfs_mount/tmp/hello_from_fuse.txt’: Input/output error