# OVSDB Error: Writing Transaction Failed: /etc/openvswitch/conf.db: Cannot Truncate: Permission Denied

## Problem

* The ***pf9-neutron-ovs-agent*** service fails to start.
* On failure, the following log trace is seen in */var/log/pf9/pf9-neutron-ovs-agent.log.*

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```none
487 189236 ERROR ovsdbapp.backend.ovs_idl.command [-] Error executing command: RuntimeError: OVSDB Error: {"details":"writing transaction failed: /etc/openvswitch/conf.db: cannot truncate to length 489420","error":"I/O error","io-error":"Permission denied"}487 189236 ERROR ovsdbapp.backend.ovs_idl.command Traceback (most recent call last):487 189236 ERROR ovsdbapp.backend.ovs_idl.command  File "/opt/pf9/pf9-neutron/lib/python2.7/site-packages/ovsdbapp/backend/ovs_idl/command.py", line 30, in execute487 189236 ERROR ovsdbapp.backend.ovs_idl.command    txn.add(self)487 189236 ERROR ovsdbapp.backend.ovs_idl.command  File "/opt/pf9/python/lib/python2.7/contextlib.py", line 24, in __exit__487 189236 ERROR ovsdbapp.backend.ovs_idl.command    self.gen.next()487 189236 ERROR ovsdbapp.backend.ovs_idl.command  File "/opt/pf9/pf9-neutron/lib/python2.7/site-packages/ovsdbapp/api.py", line 94, in transaction487 189236 ERROR ovsdbapp.backend.ovs_idl.command    self._nested_txn = None487 189236 ERROR ovsdbapp.backend.ovs_idl.command  File "/opt/pf9/pf9-neutron/lib/python2.7/site-packages/ovsdbapp/api.py", line 54, in __exit__487 189236 ERROR ovsdbapp.backend.ovs_idl.command    self.result = self.commit()487 189236 ERROR ovsdbapp.backend.ovs_idl.command  File "/opt/pf9/pf9-neutron/lib/python2.7/site-packages/ovsdbapp/backend/ovs_idl/transaction.py", line 62, in commit487 189236 ERROR ovsdbapp.backend.ovs_idl.command    raise result.ex487 189236 ERROR ovsdbapp.backend.ovs_idl.command RuntimeError: OVSDB Error: {"details":"writing transaction failed: /etc/openvswitch/conf.db: cannot truncate to length 489420","error":"I/O error","io-error":"Permission denied"}487 189236 ERROR ovsdbapp.backend.ovs_idl.command488 189236 ERROR neutron.plugins.ml2.drivers.openvswitch.agent.ovs_neutron_agent [-] OVSDB Error: {"details":"writing transaction failed: /etc/openvswitch/conf.db: cannot truncate to length 489420","error":"I/O error","io-error":"Permission denied"} Agent terminated!: RuntimeError: OVSDB Error: {"details":"writing transaction failed: /etc/openvswitch/conf.db: cannot truncate to length 489420","error":"I/O error","io-error":"Permission denied"}Traceback (most recent call last):  File "/opt/pf9/pf9-neutron/lib/python2.7/site-packages/eventlet/queue.py", line 118, in switch    self.greenlet.switch(value)  File "/opt/pf9/pf9-neutron/lib/python2.7/site-packages/eventlet/greenthread.py", line 214, in main    result = function(*args, **kwargs)  File "/opt/pf9/pf9-neutron/lib/python2.7/site-packages/ryu/lib/hub.py", line 65, in _launch    raise eSystemExit: 1
```

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## Environment

* Platform9 Managed OpenStack - v3.6.0 and Higher
* Neutron
* CentOS 7.x

## Cause

Setting ***SELinux*** to ***Enforcing*** prevents ***neutron-ovs-agent*** from connecting to */etc/openvswitch/conf.db*.

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```none
$ getenforceEnforcing
```

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## Resolution

1. On the fly, set ***SELinux*** to ***Permissive***.

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```none
# setenforce 0
```

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2. For the change to remain persistent across reboots, disable SELinux in */etc/sysconfig/selinux.*

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```none
# sed -i 's/^SELINUX=.*/SELINUX=disabled/g' /etc/sysconfig/selinux
```

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