Description of the problem

On a certain day, an OSN 3500 network element is hung under a network element in the current network, and after creating the network element and the logical connection fiber on the network management, the creation of the VC4 service layer path with the upstream station before fails, and it prompts that the resource cannot be found.

Alarm Message

Processing

1. Check the network management on the logical fiber creation is normal, to rule out the problem of no logical fiber.

2. As the equipment is newly opened, the situation of insufficient VC4 resources is ruled out.

3. Check the topology map of the network management, there is no MS path under this fiber, and a MS path will be automatically generated after the normal creation of a logical fiber, as shown in the following figure:

So the inability to create a VC4 service layer path is due to the absence of an MS path.

4. After deleting the logical fiber, upload the OSN 3500 network element and the upstream station network element, and then create the logical fiber, and found that the failure is still no MS path generation.

5. Pre-configure two network elements on the network management, and then create a logical fiber, and found that there is still no MS path generation, which proves that the MS path can not be generated because of the network management reasons, not due to the data anomaly of a network element.

6. Check the U2000 network management system monitoring, U2000 processes are normal, there is no abnormal unstarted process, the SDH end-to-end process to stop/start once, into the U2000 client found that the failure is still the same, still can not generate the MS path.

7. Check the U2000 network management system monitoring, found that the database monitoring nemgr_transDB_1 item occupies 99%, showing abnormalities, as shown in the following figure:

8. In accordance with the U2000 product documentation, "database self-growth failure" problem handling methods for manual expansion of the database, and then create a fiber-optic cable, can generate MS paths to create the VC4 service layer path is normal.

Root Cause

Insufficient space in the Network Element Manager database prevents the creation of MS paths, thus affecting the SDH path function.

Solution

The problem is solved after using manual database space expansion.