KERNSAFE - iSCSI SAN Software and Storage Virtualization

Normally, if one server stops, the storage service will be unavailable for other servers and workstations until the server start successfully. KernSafe iSCSI SAN provide a very useful feature to create a high-availability iSCSI SAN by using two or more KernSafe iSCSI SANs. When the first node fail, the other nodes will take over its work without requiring administrative intervention.

Create Clustered iSCSI SAN Node.

Step 1. Right click the Applications node on the left tree of the main window. From the pop-up menu tap the Create Application menu item.

Choose High Availability Node in the Application Type.

Press the Next button to continue.

Step 2. Configure Failover.

Firstly, choose one target as the base target. Then press the setting button to find the Partner Target.

After you input the host name and port of the remote iSCSI, press the Discovery button, it will show you all the targets on the remote iSCSI, select one and press the OK button.

If the target you choose has the CHAP authorization, you must provide the user name and secret to log on.

Then press the Next button to continue.

Step 3. Synchronization Settings

In this window you can specify all parameters for synchronization settings, such as Port Address or data dump folder.

Note: With the new version of KernSafe iSCSI SAN, we have improved HA feature which can use multiple NICs to do Sync to prevent Spilt-Brain.

User must specify parameters for Sync Channel and can scroll up the window and specify more channels for alternatives, these alternatives work as heart-beat and can be used when Sync channel got broken, these alternatives will prevent split-brain.

Press Next button to continue.

Step 4. Mirror Synchronization

Now, the mirror target should be synchronized to the base target, if the two targets are both the new one and do not be initialized, we can choose Create mirror device without synchronization (Manual Initialization), otherwise, we must choose Create mirror device with full synchronization from base iSCSI target.

Note: All data on the mirror device will be destroyed after synchronization.

Step 4. Complete Application Creation

Press the Finish button to complete Application creation.

Repeat Step 1 to Step 4, to create failover application on another server.

After application will be created on both nodes, you can check it status by clicking on Applications in left side panel.
Depending on the status of this failover application, you may notice following types:

 • Running:
  Indicate that both current and partner servers are working without any problem.
• Failed:
  Indicate that partner server doesn’t work, and current target is working only with single path.
• Synchronizing:
  Indicate that current server is synchronizing data to partner server.
  Warning:
  Don’t shutdown, reboot or stop KernSafe iSCSI SAN, otherwise later you will need to manually synchronize data to partner server.
• Pending:
  Indicate that partner server is synchronizing data to current server.
• Inconsistent
  Indicate two servers have different data and should do synchronization.

Configuring Windows Server 2008

Install MPIO Feature
Launch Start->Administrative Tools->Server Manager, go to Features item, click Add Features.
An Add Features Wizard will appear. In the features list select Multipath I/O feature and install it.

Connect Targets
Lunch the Administrative Tools -> Microsoft iSCSI initiator.
Switch to the Discovery tab. Add each of the KernSafe iSCSI SANs by clicking the Discover Portal…  button and specifying server IP address.

Switch to the Targets tab.

Connect the targets by clicking the Connect button.
A Connect To Target dialog will be shown.
Check Add this connection to the list of Favorite Targets.

Click the OK button to connect the target.

Now, the client is connected to the two targets.

Enable Multipath Support
Launch MPIO manager by clicking Start->Administrative Tools->MPIO. Go to Discover Multi-Paths tab, check Add support for iSCSI devices.

Click the Add button.
Windows will prompt you to reboot the server.

Click the Yes button to restart your server.

We have to initialize the disk before we use it.
Click Start->Computer->Manage->Disk Management, the Initialize and Convert Disk Wizard window will be shown.

Check Disk 2 and press OK to finish the initialization.

Right click on the Disks and then select New Simple Volume, partition and format the two disks followed by wizard.
If successful, the new volumes created are shown in the figure below.

Configuring Windows Server 2003

Enable Multipath Support
Download Microsoft iSCSI Initiator and install it with the Microsoft MPIO Multipathing Support for iSCSI option enabled.

You will need to restart computer before continuing.

Connect to target
Launch the MS iSCSI Initiator by selecting Start->All Programs->Microsoft iSCSI Initiator.
Switch to the Discovery tab. Add each of the KernSafe iSCSI SANs by clicking the Add button and specifying server IP address.

Switch to the Targets tab.

Connect the targets by clicking the Log On… button.
A Log On to Target dialog will be shown.
Check Automatically restore this connection when the system boots.

Target 1

Target 2

Click the OK button to connect the target.

Now, the client is connected to the two targets, we have to initialize the disk before we use it.