Troubleshooting EV DCOM errors

[Nathan_Clark_2]

EV uses DCOM a lot so sometimes, we encounter DCOM errors, theses usually bubble up to the application level:

Check that this server is available and try again.

Could not connect to the Enterprise Vault.

The RPC server is unavailable.

service is not running on the destination server

etc etc.

If you Dtrace (and filter VaultCoCreateInstance) the component in question:

You should see the wrapper (around CoCreateInstanceEx which creates the COM object) call:

VaultCoCreateInstanceEx: An error occurred - RequestedServerName = [NathansEV], UsedServerName = [REMOTESERVER], hrCCI = [0x800706BA]...

Exposing  the Error: [0x800706BA] and server name

Or check the System Event log (where you usually find more info like the CLSID) on windows 2008 for the 10009 errors:

DCOM got error "2147746132" from the computer 192.168.75.134 when attempting to activate the server:

{GUID OF OBJECT}

Here error 2147746132 a common one and a bit generic is:

hex 0x80040154 :

  REGDB_E_CLASSNOTREG                                           

Which usually implies that GUID is not registered in the registry on that server, a regsvr32 on the relevant dll may help, or a DCOM permissions issue

DCOM was unable to communicate with the computer REMOTESERVER using any of the configured protocols.

If you check the eventids Details you can see the status code:

0038: 33 3B 53 74 61 74 75 73 3;Status
0040: 3D 31 37 32 32 3B 47 65 =1722;Ge
0048: 6E 63 6F 6D 70 3D 32 3B ncomp=2;
0050: 44 65 74 6C 6F 63 3D 31 Detloc=1
0058: 37 31 30 3B 46 6C 61 67 710;Flag
 

C:\tools>net helpmsg 1722

The RPC server is unavailable.

This usually implies some transport error

ping REMOTESERVER?

telnet REMOTESERVER 135?

Also to help troubleshooting, is the CreateObjectfromGuid.exe utility in the Download section

M:\>CreateObjectfromGuid.exe
Enter remote server:
NATHAN-PC
StorageOnline:F019A230-FF92-11D1-8C20-0000F87502DE IE:0002DF01-0000-0000-C000-000000000046
Enter GUID for object:
0002DF01-0000-0000-C000-000000000046
SO Type System.__ComObject
SO Object Created ok on NATHAN-PC 0002df01-0000-0000-c000-000000000046

Here we can check we can create a generic (Internet Explorer IE) object, to help narrow down the issue, or use the GUID thats failing in System Event log.

If you receive access denied:

Exception calling "CreateInstance" with "1" argument(s): "Retrieving the COM class factory for remote component with CLSID

{2D198DCA-C1F8-49F2-9A7E-169016F562F7} from machine NathanEV failed due to the following error: 80070005."

Reset the VSA in the VAC, and check DCOM perms as per:

http://www.stuffthatjustworks.com/SearchView.aspx?q=UnauthorizedAccessException

or use Powershell

PS 32-bit Powershell running as VSA prompt> [Activator]::CreateInstance([Type]::GetTypeFromCLSID([Guid]'{2D198DCA-C1F8-49F2-9A7E-169016F562F7}',"REMOTESERVER"))