Hello Diramos, That is a tough one as OMSA stopped supporting the older 8th gen systems back in 6.x   OMSA 6.5 works with 8th Gen but most customers find the 5.5 most stable with 8th gen systems.  Now, the other issue is that Sever 2012 is not listed as a supported OS for Dell 8th gen systems either.  Obviously it works, since you have it installed, but you may run into compatibility issues.  Especially like this this where there is not a systems management configuration that will work well.  Windows 2008 R2 will work OMSA 6.5.   Let us know if you have further questions.   
Hi, Masters!I installed Dell OMSA 7.4 (OM-SrvAdmin-Dell-Web-WINX64-7.4.0-866_A00) package on my Poweredge 6850 with Windows Server 2012 - Datacenter. Everything works fine, except for the storage controller. The OMSA displays the message: no storage controllers found. Can you help me? Thank youDiramos
Dell Openmanage 7.4, 64 bits on Poweredge 6850 with Windows 2012 Server 
Datacenter does not recognize the storage controllers