I was working with the Dell Equallogic Management pack, v.4.1 and had problems getting it to discover the SAN ifself.

The customer had installed the DLL-Helper utility on both of the nodes on the RMS-Cluster and in the log we found the following:

Discovery data couldn't be inserted to the database. This could have happened because  of
one of the following reasons: 

       - Discovery data is stale. The discovery data is generated by an MP recently deleted.

       - Database connectivity problems or database running out of space.

       - Discovery data received is not valid.

The following details should help to further diagnose:



DiscoveryId: 9513b193-84d2-fb5d-51ae-f8359217e0a6

HealthServiceId: a919d879-654f-cef7-d15d-b217a92eb402

Invalid relationship source specified in the discovery data item.

RelationshipSourceBaseManagedEntityId: bec5d4e3-0a57-4b5c-7d71-301eba07a245

RuleId: 9513b193-84d2-fb5d-51ae-f8359217e0a6

Instance:

<?xml version="1.0"
encoding="utf-16"?><RelationshipInstance
TypeId="{70b5e304-cf58-b3a8-59c4-07d9ee19b2da}"
SourceTypeId="{ab4c891f-3359-3fb6-0704-075fbfe36710}"
TargetTypeId="{89a9f18f-0d72-48fe-5794-382c0f6f1ff7}"><Settings
/><SourceRole><Settings><Setting><Name>5c324096-d928-76db-e9e7-e629dcc261b1</Name><Value>SCOM Cluster Node</Value></Setting></Settings></SourceRole><TargetRole><Settings><Setting><Name>5c324096-d928-76db-e9e7-e629dcc261b1</Name><Value>SCOM Cluster Node<Value></Setting><Setting><Name>4f8832c6-1432-19bb-15b5-5a895390a399</Name><Value>10.16.32.55</Value></Setting></Settings></TargetRole></RelationshipInstance>.

It turned out the the discovery can't combine the SAN with a clustered RMS and installing the DLL-Helper utility on a standalone Management server and using that as the Proxy Agent solved the problem.

Conclusion, the Dell Equallogic MP v.4.1, DLL-Helper utlity, needs to be installed on a non-clustered Management server.