# Find the missing VMs and Hosts - VMware

After the vCenter discovery, if the VMs and Hosts are missing, query the below table and check:

```sql
select * from vwentitymomapping where entity_type = 'VirtualMachine';
```

```sql
select * from vwentitymomapping where entity_type = 'HostSystem';
```

When the MOID is **-3**, Virtual machines have not been selected by the user to be monitored. By clicking on **Update inventory** option in vCenter device snapshot page, list of virtual machines and hosts which are available will be listed. Select the VMs which have to be monitored.

When the MOID is **-4**, check whether their DNS resolves. If not, update it from vSphere client › host property.

When the MOID is **-5**, that's marked as **"deleted by user"**, so **OpManager** won't be mapping it.

We have to run this update query manually and restart **OpManager** service:

```sql
update vwentitymomapping set moid = -4 where moid = -5;
```

Now automatic discovery will initiate during every restart.

## Frequently asked questions:

1. [How to discover devices and interfaces in OpManager?](https://www.manageengine.com/network-monitoring/help/discover-networks.html)
2. [How to add a new credential?](https://www.manageengine.com/network-monitoring/help/add-credentials.html)
3. [Can I add a non-admin user account for WMI?](https://www.manageengine.com/network-monitoring/kb/adding-non-admin-user-for-wmi.html)
4. [Can I add devices using SSH?](https://www.manageengine.com/network-monitoring/help/adding-devices-using-ssh.html)
5. [Why are devices discovered as 'Unknown'?](https://www.manageengine.com/network-monitoring/faq/devices-discovered-as-unknown-devices-opmanager.html)
6. [What are devices supported in OpManager?](https://www.manageengine.com/network-monitoring/faq/all-devices-supported.html)
7. [Why are interfaces not discovered for my device?](https://www.manageengine.com/network-monitoring/faq/interfaces-not-discovered.html)
8. [How can I associate device templates to a newly discovered device?](https://www.manageengine.com/network-monitoring/help/associate-device-template.html)
9. [How to associate monitors to the discovered device?](https://www.manageengine.com/network-monitoring/help/adding-custom-monitors.html)
10. [What is a discovery filter?](https://www.manageengine.com/network-monitoring/help/discovery-filter.html)
11. [How do I configure a new discovery rule?](https://www.manageengine.com/network-monitoring/help/configuring-discovery-rule-engine.html)
12. [How to manage or unmanage a device?](https://www.manageengine.com/network-monitoring/help/managing-and-unmanaging-a-device.html)
13. [How to configure device dependencies?](https://www.manageengine.com/network-monitoring/help/configuring-device-dependencies.html)
14. [How can I discover a VLAN?](https://www.manageengine.com/network-monitoring/faq/vlan-discovery-in-opmanager.html)
15. [How does availability monitoring work in OpManager?](https://www.manageengine.com/network-monitoring/availability-monitoring.html)
16. [What are the basic system requirements to install and use OpManager?](https://www.manageengine.com/network-monitoring/help/hardware-and-software-requirements.html)
17. [How can I troubleshoot issues with device discovery?](https://www.manageengine.com/network-monitoring/help/add-device-failure-messages.html)
18. [How can I troubleshoot issues with VCenter/ESX discovery?](https://www.manageengine.com/network-monitoring/faq/troubleshooting-problems-in-vcenter-discovery.html)