Eyeglass Solutions Publication
Installation Guide




Solution Description

This solution consists of two modules:

  1. Microsoft Cluster Network Load Balancing with autonomous Failover
  2. System Information Gathering


Microsoft Cluster Network Load Balancing with Autonomous Storage Failover


The Microsoft Network Load Balancing (NLB) manages two or more servers as a single virtual cluster. Typical use cases of NLB enhance the availability and scalability of Internet server applications such as those used on web, FTP, firewall, proxy, virtual private network (VPN), and other mission-critical servers.


The NLB feature distributes traffic across several servers by using the TCP/IP networking protocol. By combining two or more Windows Servers that are running applications into a single virtual cluster, NLB provides reliability and performance for web servers and other mission-critical servers.


NLB Cluster Host Setting

The servers in an NLB cluster are called hosts, and each host runs a separate copy of the server applications. NLB distributes incoming client requests across the hosts in the cluster. We can configure the load that is to be handled by each host. We can also add hosts dynamically to the cluster to handle increased load. NLB can also direct all traffic to a designated single host, which is called the default host.


NLB allows all of the computers in the cluster to be addressed by the same set of IP addresses, and it maintains a set of unique, dedicated IP addresses for each host. For load-balanced applications, when a host fails or goes offline, the load is automatically redistributed among the computers that are still operating. When it is ready, the offline computer can transparently rejoin the cluster and regain its share of the workload, which allows the other computers in the cluster to handle less traffic.

Autonomous Storage Failover


NLB provides high availability and redundancy from application server perspective but it does not include the mechanism to handle Storage Failover. Additional solution is needed to include the mechanism to handle storage failover automatically. This solution guide is based on the integration of Superna Eyeglass DR Edition - DFS Mode failover and  Dell EMC PowerScale.


Solution Diagram


Example of the solution for Internet Web Server application that consists of the following:



  1. Microsoft
    1. Network Load Balancing (NLB) Cluster with minimum 2 Windows Servers as Windows Cluster Nodes
    2. Internet Information Services (IIS) is running on each Windows Cluster nodes with data directory structure stored on the storage Production PowerScale cluster (SMB Share)
    3. DFS Server - data on the PowerScale is accessed through DFS namespace
  2. Dell EMC
    1. 2 PowerScale Clusters: Production and DR clusters
  3. Superna
    1. Eyeglass DR




Solution Overview

  1. Internet Information Services (IIS) is running on both Windows Servers. The data for this application is stored on the PowerScale Cluster (Prod) and accessed through SMB Share via DFS Namespace.
  2. Microsoft Network Load Balancing (NLB) Cluster is configured by adding both Windows Servers as member servers of NLB. Host priority value is set for assigning Windows Servers as Primary and Secondary server.
  3. Stored data on the Prod PowerScale storage is replicated to DR PowerScale storage through SyncIQ Policy replication
  4. Eyeglass DR is configured to replicate PowerScale Cluster configuration (e.g. SMB Share configuration), provide Failover Readiness status, and manage storage failover (DFS mode failover)
  5. PowerShell code is configured  to monitor NLB node status and Data accessibility from Production PowerScale. This PowerShell code is running on the Secondary NLB node.
  6. PowerShell code
    1. Upon detecting Primary NLB node not converged or no longer part of NLB, it will send alert
    2. Upon detecting Production PowerScale not accessible, it will send alert and initiate Eyeglass DFS mode failover automatically



System Information Gathering

The second module is System Information Gathering. System Information is a collection of technical information on the overall system and resources that also includes diagnostic and troubleshooting information related to the system.


The common use case is for collecting system information of remote systems from a local management system for inventory collection tasks and troubleshooting.



Solution Diagram




Solution Overview


This module is to gather system information of remote machines from a local management system (Eyeglass appliance).

This module is based on Python3 code that calls and executes Operating System command / script remotely over SSH. It consists of 3 sub-modules to gather system information from three different components: Powerscale cluster, Linux server, Windows server.


The current module consists of 3 sections that collects the following information (can be added with additional information gathering):



SectionSystem Information Gathering
  • OneFS version
  • Status
Linux Machine
  • OS version
  • Python version
  • System Information (e.g. hostname, cpu/memory usage)
  • Network information
  • Log collection from /var/log directory
Windows Machine
  • System Information
  • Event Logs
  • Network Information


PowerScale System Information

Two information is gathered from PowerScale Cluster:



System InformationCommand
OneFS versionisi version
PowerScale statusisi status -v


The SSH session from Eyeglass to PowerScale is using eyeglass service account that has been configured on the PowerScale with permissions and privileges by following this Eyeglass documentation

If need additional command to run on PowerScale using eyeglass service account, we need to update the permissions and privileges accordingly


Linux Server System Information

The following information is gathered from Linux Server:



System InformationCommand
Linux OS versioncat /etc/os-release
Python versionpython3 -V
Network informationIfconfig
Log zip /var/log and copy zip file to local




Product Name


Serial Number

Machine Type

Operating System



Processor Name

Active User

System Main IP



cat /sys/class/dmi/id/chassis_vendor

cat /sys/class/dmi/id/product_name

cat /sys/class/dmi/id/product_version

cat /sys/class/dmi/id/product_serial



uname -r




hostname -I

Memory Usage

Swap Usage

CPU Usage



cat /proc/stat


The SSH session from Eyeglass to Linux Server is using root account

Using a non root account on the linux server might require additional sudo privileges configuration.



Windows Server System Information

The following information is gathered from Windows Server:



System InformationCommand
Event Logwevtutil epl
Overall System Informationmsinfo32
Network informationGet-NetAdapter


The SSH session from Eyeglass to Windows Server is using Administrator account

Using a non Administrator account on the Windows server might require additional permission configuration on Windows server.




Firewall Requirements


SSH connections need to be established from Eyeglass Appliance to PowerScale, Linux Servers, and Windows Servers.


22TCPEyeglass appliance → Isilon/PowerScale clusterSSH
22TCPEyeglass appliance → Linux machinesSSH
22TCPEyeglass appliance → Windows machinesSSH






Microsoft Cluster Network Load Balancing



Microsoft Documentation



We can use Microsoft  Network Load Balancing (NLB) NLB to manage two or more Windows servers as a single virtual cluster. NLB enhances the availability and scalability of Internet server applications such as those used on web, FTP, firewall, proxy, virtual private network (VPN), and other mission-critical servers.



Hardware requirements

Following are the hardware requirements to run an NLB cluster.


  • All hosts in the cluster must reside on the same subnet.
  • There is no restriction on the number of network adapters on each host, and different hosts can have a different number of adapters.
  • Within each cluster, all network adapters must be either multicast or unicast. NLB does not support a mixed environment of multicast and unicast within a single cluster.
  • If you use the unicast mode, the network adapter that is used to handle client-to-cluster traffic must support changing its media access control (MAC) address.


Software requirements

Following are the software requirements to run an NLB cluster.


  • Only TCP/IP can be used on the adapter for which NLB is enabled on each host. Do not add any other protocols (for example, IPX) to this adapter.
  • The IP addresses of the servers in the cluster must be static.


Installation Procedure

We can install NLB by using either Windows Server Manager or the Windows PowerShell commands for NLB.


Optionally we can install the Network Load Balancing Tools to manage a local or remote NLB cluster. The tools include Network Load Balancing Manager and the NLB Windows PowerShell commands.


Installation with Server Manager

Note : We need to perform the following steps on each member server that are going to participate in the NLB cluster.


  1. On the Member Server, open Server Manager. Click on Manage Menu  and select Add Role and Features.




  1. On the Before you begin page, click Next.




  1. Select Role-based or feature-based installation and click Next



  1. Select a server from the Server Pool on which we want to install the Network Load Balancing feature, click Next.



  1. On the select Server Roles page, click Next



  1. On the select Features, select Network Local Balancing checkbox.


  1. A new window will pop up, click on Add Features to include required features and management tools for Network Local Balancing work properly.


  1. Click Next to proceed with confirmation


  1. Click on the Install button to start the installation process





Alternative Installation using PowerShell Command


To install NLB by using Windows PowerShell, run the following command at an elevated Windows PowerShell prompt on the computer where you want to install NLB.


Install-WindowsFeature NLB -IncludeManagementTools



Windows PowerShell

Copyright (C) Microsoft Corporation. All rights reserved.


PS C:\Users\Administrator> Install-WindowsFeature NLB -IncludeManagementTools


Success Restart Needed Exit Code      Feature Result

------- -------------- ---------      --------------

True    No             Success        {Network Load Balancing, Remote Server Adm...




Application Server : Microsoft Internet Information Services (IIS) Installation

Microsoft IIS needs to be installed on each member server of NLB.


The procedure to install IIS by using PowerShell command:


  1. Open PowerShell with administrative privileges and run the Install-WindowsFeature cmdlet:


Install-WindowsFeature -name Web-Server -IncludeManagementTools



Windows PowerShell

Copyright (C) Microsoft Corporation. All rights reserved.


PS C:\Users\Administrator> Install-WindowsFeature -name Web-Server -IncludeManagementTools


Success Restart Needed Exit Code      Feature Result

------- -------------- ---------      --------------

True    No             Success        {Common HTTP Features, Default Document, D...





  1. Once the installation has succeeded, IIS should be running on port 80 by default with the firewall rule “World Wide Web Services (HTTP Traffic-In)” enabled in Windows firewall automatically.
  2. We can perform a simple test by opening up a web browser and browsing to the server that we have installed IIS on. We should see the default IIS page




Eyeglass Installation

Refer to Eyeglass Installation Document



We can use the  default python3 that is already installed on the Eyeglass appliance.


Additional Python Module

The following additional Python module is required:

  • urllib3


To install this additional module on the Eyeglass we can use this command:

pip install urllib3





OpenSSH on Windows installation


We need to install OpenSSH Server on the Windows servers to allow Eyeglass to establish SSH sessions to those servers for command execution. For installation OpenSSH on Windows, refer to Microsoft documentation


Example for installing OpenSSH Server on Windows Server 2019



  1. Open Settings, select Apps, then select Optional Features.
  2. Scan the list to see if the OpenSSH is already installed. If not, at the top of the page, select Add a feature, then find OpenSSH Server then select Install
  3. Once setup completes, return to Apps and Optional Features and confirm OpenSSH is listed.
  4. Open the Services desktop app. (Select Start, type services.msc in the search box, and then select the Service app or press ENTER.)
  5. In the details pane, double-click OpenSSH SSH Server.
  6. On the General tab, from the Startup type drop-down menu, select Automatic.
  7. To start the service, select Start.


Start SSH services on windows


From PowerShell console, we can use the following command to show the status of the SSHD service:


PS C:\Users\Administrator> get-service | findstr ssh


Stopped  ssh-agent          OpenSSH Authentication Agent

Stopped  sshd               OpenSSH SSH Server



To start the service:


PS C:\Users\Administrator> Start-Service sshd

PS C:\Users\Administrator> Start-Service ssh-agent


Once started it should show the running state


PS C:\Users\Administrator> get-service | findstr ssh

Running  ssh-agent          OpenSSH Authentication Agent

Running  sshd               OpenSSH SSH Server





© Superna Inc