can't delete bad node from the cluster

[#1]

64-node cluster

one node is bad..no longer communicates 

I want to remove him from the cluster

ch-8	10.71.0.108	/default	CDH 5	Cluster 1	2 Role(s)	Good Health	12.38s ago
ch-9	10.71.0.109	/default	Unknown	Cluster 1	2 Role(s)	Bad Health	None

here he is in the hosts. he's a data node and a nodemanager (yarn)

When I try to delete, it tells me

Delete Hosts The following 1 host(s) cannot be deleted because they have role instances or are not completely decommissioned:

Host Role Instances

ch-9	nodemanager (ch-9) and 1 other role(s).

If I try this, it doesn't work Remove Hosts From Cluster

Removing these hosts will stop and delete all roles running on them and then remove them from their clusters. The hosts will still be managed by Cloudera Manager and can be utilized after being added to new or existing clusters.
Role data directories will not be deleted.

Host Role

ch-9	NodeManager, DataNode

Decommission Roles (Warning: Removing the hosts without decomissioning the roles running on them can result in permanent data loss.) Skip Management Roles   

Command Details: Hosts Decommission

Command Context Status Started at Ended at

Hosts Decommission	Finished	Mar 31, 2014 1:09:28 PM PDT	Mar 31, 2014 1:09:28 PM PDT
Command 'DecommissionWithWait' failed for service 'yarn'

Child Commands

All   Failed Only   Active Only

Command (Child commands) Context Status Started at Ended at

Decommission (2)	YARN (MR2 Included)	Finished	Mar 31, 2014 1:09:28 PM PDT	Mar 31, 2014 1:09:28 PM PDT
Failed to perform decommission.

 Basically, if I can't talk to the node, I can't stop/decommission/delete him How should I do it?

[#2]

Please check the permission for the nodemanager directory. The owner or group must be yarn.

Then try to decommission and it will distribute the blocks to other datanodes and then will decommission.