KERNSAFE - iSCSI SAN Software and Storage Virtualization

In a single-server deployment, storage services become unavailable if that server stops unexpectedly. KernSafe iSCSI SAN can be configured as a high-availability cluster by using two or more nodes. If one node fails, another node can take over service automatically without requiring administrator intervention.

Creating a Clustered iSCSI SAN Node

Step 1. Right-click the Applications node in the left tree of the main window, then choose Create Application.

Select High Availability Node as the application type.

Click Next to continue.

Step 2. Configure failover.

Select the base target, then click the Setting button to locate the Partner Target.

Enter the host name and port of the remote iSCSI server, then click Discovery to retrieve the available targets. Select the required target and click OK.

If the selected target requires CHAP authentication, provide the user name and secret.

Click Next to continue.

Step 3. Configure synchronization settings.

In this window you can specify synchronization parameters such as the Port Address and the data dump folder.

Note: Newer versions of KernSafe iSCSI SAN allow multiple NICs to be used for synchronization in order to reduce the risk of split-brain conditions.

Specify the main synchronization channel, then scroll through the window to configure additional channels. These secondary channels act as heartbeats and can take over if the primary synchronization channel fails.

Click Next to continue.

Step 4. Choose the mirror synchronization mode.

If both targets are new and uninitialized, you can choose Create mirror device without synchronization (Manual Initialization). Otherwise, choose Create mirror device with full synchronization from base iSCSI target.

Note: All data on the mirror device is destroyed during full synchronization.

Step 5. Complete application creation.

Click Finish to create the application.

Repeat Steps 1 through 5 on the partner server so that the failover application exists on both nodes.

After the application has been created on both nodes, click Applications in the left pane to check its status.
Possible status values include:

Running: Both the current server and the partner server are operating normally.
Failed: The partner server is unavailable, and the current target is running in single-path mode.
Synchronizing: The current server is synchronizing data to the partner server.
Warning: Do not shut down, reboot, or stop KernSafe iSCSI SAN while synchronization is in progress, or you may need to resynchronize manually later.
Pending: The partner server is synchronizing data to the current server.
Inconsistent: The two servers contain different data and synchronization is required.

Configuring Windows Server 2008

Install the MPIO feature
Open Start -> Administrative Tools -> Server Manager, select Features, and click Add Features.
In the Add Features Wizard, select Multipath I/O and install it.

Connect the targets
Open Administrative Tools -> Microsoft iSCSI Initiator.
On the Discovery tab, add each KernSafe iSCSI SAN node by clicking Discover Portal... and entering the server IP address.

Switch to the Targets tab.

Connect the targets by clicking Connect.
In the Connect To Target dialog box, select Add this connection to the list of Favorite Targets.

Click OK to connect the target.

The client is now connected to both targets.

Enable multipath support
Open the MPIO manager from Start -> Administrative Tools -> MPIO. On the Discover Multi-Paths tab, select Add support for iSCSI devices.

Click Add.
Windows prompts you to restart the server.

Click Yes to restart the server.

Before using the disk, initialize it.
Open Start -> Computer -> Manage -> Disk Management. The Initialize and Convert Disk Wizard appears.

Select Disk 2 and click OK to complete initialization.

Right-click the disks, choose New Simple Volume, then partition and format the two disks by following the wizard.
When the process is complete, the new volumes appear as shown 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.

Restart the computer before continuing.

Connect to the target
Open the Microsoft iSCSI Initiator from Start -> All Programs -> Microsoft iSCSI Initiator.
On the Discovery tab, click Add for each KernSafe iSCSI SAN node and enter the server IP address.

Switch to the Targets tab.

Connect the targets by clicking Log On....
In the Log On to Target dialog box, select Automatically restore this connection when the system boots.

Target 1

Target 2

Click OK to connect the target.

The client is now connected to both targets. Use Windows Disk Management to initialize, partition, and format the disk before putting it into service.