Highly Available Storage using Samba-AD and AD DFS

A Virtual Server example hosting a DFS namespace with multiple Samba-AD deployments for high availability

In this example, a Distributed File System (DFS) Namespace leveraging multiple Samba-AD deployments for high availability is provisioned onto CoreWeave Cloud.

This process consists of adding the Distributed File System Namespace role to a previously deployed Domain Controller, as well as deploying multiple Samba-AD instances presenting Shared Filesystem storage volumes. Each Samba-AD instance is added to the DFS Namespace so that shares are highly available.

Prerequisites

This example presumes that a Windows Server with an Active Directory Domain has already been deployed. It is also presumed that the user already has an active CoreWeave account and has configured their user credentials such that resources may be deployed to their namespace.

Create Storage Volumes

Before deploying the Samba-AD instance, there must be storage volumes to present. The Samba-AD instance will use three Shared HDD Filesystems. To create these, the user navigates to the Storage section of the CoreWeave Cloud UI.

In this example, three volumes are used for the Samba-AD instance. They are each titled vol01, vol02, and vol03 respectively.

Deploy Samba-AD Instances

With the storage volumes allocated, they may now be presented with Samba-AD.

Samba-AD is installed from the Cloud UI Applications Catalog by searching samba-ad. Click the samba-ad card, then click the Deploy button to configure and launch Samba-AD.

Configure Samba-AD

The Samba-AD application requires some details prior to deploying. In this example, the same details provided in the Windows Server with Active Directory Domain example are used to fill out the form, including the instance name. At the bottom of the deployment form, the filesystem volumes created earlier (vol01, vol02, and vol03) are attached at the end of the form, before the application is deployed.

The post-deployment status page indicates when the deployed Samba-AD Pods are in a Ready state.

Create a second Samba-AD instance

Repeating the steps above, a second Samba-AD instance is created, this one given the name smbad02.

Note

Samba-AD includes an podAntiAffinity to prevent multiple instances from being scheduled on the same compute node.

Configure the Distributed File System

With both Samba-AD instances deployed, the DFS Namespace can be configured.

A new PowerShell session on the desired DFS Namespace server - usually, the Primary Domain Controller - is opened with an authenticated administrative Domain Account. The following commands are issued to configure the DFS Namespace.

Install the DFS Namespace role

First, the DFS Namespace role is created.

Install-WindowsFeature -Name FS-DFS-Namespace,FS-DFS-Replication  -IncludeManagementTools

Success Restart Needed Exit Code      Feature Result
------- -------------- ---------      --------------
True    No             Success        {DFS Namespaces, DFS Replication, DFS Mana...

Setup DFS root folder structure

Next, the DFS root folder structure is created.

New-Item -ItemType Directory $env:SystemDrive\DFSRoots\Shares -Force


    Directory: C:\DFSRoots


Mode                 LastWriteTime         Length Name
----                 -------------         ------ ----
d-----         3/31/2022  12:57 AM                Shares

Create DFS root SMB share

Then, a DFS root SMB share is provisioned.

New-SmbShare -Name "Shares" -Path $env:SystemDrive\DFSRoots\Shares

Name   ScopeName Path               Description
----   --------- ----               -----------
Shares *         C:\DFSRoots\Shares

Create the DFS Namespace root

In this example, vs-pdc is the Domain Controller we are using for our DFS Namespace host. The directory Shares is the directory created and shared previously.

New-DfsnRoot -TargetPath "\\vs-pdc\Shares" -Type DomainV2 -Path "\\ad\Shares"

Path        Type      Properties TimeToLiveSec State  Description
----        ----      ---------- ------------- -----  -----------
\\ad\Shares Domain V2            300           Online

Create DFS Targets

For each Samba-AD instance created, a DFS folder target is created. This process is repeated for each share the Samba-AD instance presents. In this example, the process must be replicated for volumes vol02 and vol03.

New-DfsnFolderTarget -Path "\\ad\shares\vol01" -TargetPath "\\smbad01\vol01"

Path              TargetPath      State  ReferralPriorityClass ReferralPriorityRank
----              ----------      -----  --------------------- --------------------
\\ad\shares\vol01 \\smbad01\vol01 Online sitecost-normal       0

New-DfsnFolderTarget -Path "\\ad\shares\vol01" -TargetPath "\\smbad02\vol01"

Path              TargetPath      State  ReferralPriorityClass ReferralPriorityRank
----              ----------      -----  --------------------- --------------------
\\ad\shares\vol01 \\smbad02\vol01 Online sitecost-normal       0

Verify the results

Navigating to \\ad\Shares, each DFS folder target should now exist, as shown here:

Under Properties, in the DFS tab, smbad02 is shown as the currently active file server.

Copying a file to the DFS Root Folder path demonstrates that the file gets copied to the shares presented by the Samba-AD instances:

Adding a secondary DFS Namespace Server

To mitigate any points of failure, we will use the secondary domain controller created earlier as an additional DFS Namespace server.

The following steps will be repeated in order to accomplish this:

1. Install the DFS Namespace Role

2. Setup DFS Root Folder Structure

3. Create DFS Root SMB Share

4. Create DFS Namespace Root (In this step, vs-pdc is substituted with vs-dc2)

Once complete, multiple Root Target Paths are visible by using Get-DfsnRootTarget \\ad\shares:

Get-DfsnRootTarget \\ad\shares

Path        TargetPath                                                           State  ReferralPriorityClass ReferralPriorityRank
----        ----------                                                           -----  --------------------- --------------------
\\ad\shares \\vs-pdc.ad.tenant-orgname-namespace.svc.tenant.chi.local\Shares Online sitecost-normal       0
\\ad\shares \\vs-dc2.ad.tenant-orgname-namespace.svc.tenant.chi.local\Shares Online sitecost-normal       0