Domain Controllers - DCDiag & Repadmin

All system engineers have experienced replication problems once in a lifetime.Today I will show you some basic commands to Troubleshoot and Diagnose Domain Controllers and replications. I'm talking about DCDiag and Repadmin.

DCDiag:

This command-line tool analyzes the status of one or all domain controllers in a forest and reports all problems to provide assistance in troubleshooting. DCDiag.exe consists of a variety of tests that can run either individually or as part of a set to check the state of the domain controller. Here are some examples:

1. Preparing to install or migrate to Exchange;
2. Checking FSMO roles;
3. Troubleshooting Group Policies;
4. Investigating Active Directory not replicating frssysvol error;
5. Running down Kerberos authentication problems;
6. Resetting the Directory Service Administrator's password;
7. Fixing a servers Service Principle Name (SPN) error.

Repadmin

Performs replication-related tasks, such as managing and modifying replication topology, forcing replication events, and viewing replication metadata and updated vectors.

Let's see some examples and a Script to automize all Domain Controllers replication.

SCCM - Failed to validate content hash on Distribution Point. Yellow Warning

In SCCM when there are many Distribution Points with different published Software, it may happen that there are validation failures and that WMI repository is inconsistent. The events are represented as in the following table:

 

SCCM by default does not have any tools that allow you to resynchronize the entire WMI repository without removing the Distribution Point Role and adding it again. Let's see how to get around this.

Office 365 Users Not able to view Free/Busy and Room information of On-Premises

The other day I had to validate and solve a problem with calendar synchronizations between Office 365 and Exchange 2010 (and vice verse). I was aware that On-Premises users could see the status of all users calendars, but Office 365 users only could see the Office 365 users status. (Office 365 users were not able to view F/B information of On- Premises user mailboxes).

This scenario is valid for Exchange 2010/2013 and Office 365 hybrid architectures with or without ADFS. The errors that I had were this:

Trying to share a Calender between On-Prem and an Office 365 User:

"One or more users cannot be added to the folder access list"

The outlook/webmail calendar had errors:

"No Information. No free/busy information could be retrieved"

"The recipient's server could not be contacted. Contact your administrator"

Let's see the necessary steps for the resolution.

Create Multiple Mount Points in Multiple Disks in one Datastore VMware

I was in a costumer where I had to create many disks to present to several virtual machines in VMware. The Datastores were few, but I had to create 60 disks in each VM (maximum supported with four SCSI controllers). To increase complexity, all of these Volumes in Windows meant to be Mount Points. To optimize this process I had to create some Scripts to help me.

I splited in different points:

• Script to add multiple disks from one datastore to a VM;
• Script to change all the Disks paths to Round Robin (The Storage was a HPE 3PAR);
• Script to Create all the Windows Mount Points;
• Script to view the Mount Points created.

Let's see how to do it!