This section describes how to configure a CHARON-VAX for a Windows CI cluster.

A virtual CIXCD is the functional equivalent of a hardware CIXCD host adapter with the exception that there is no physical layer to connect to a hardware CI infrastructure. The current hardware is much faster than the physical CI implementation, therefore if such a connection were even possible, it would limit the virtual system throughput.

For data storage, the CIXCD connects to one or more virtual HSJ50 controllers that are loaded as separate components in the configuration file. To configure VAX CI clusters, the virtual CIXCDs of the multiple CHARON virtual machines (VMs) are interconnected via TCP/IP links.

It is advisable to start any field test based on the cluster examples provided below

Configuring virtual CI clusters requires many configurable parameters and these parameters need to be the same on all servers.

The current CI implementation for CHARON-VAX/66x0 supports up to 8 VAX VMs in a virtual CI cluster and handles a maximum cluster size of 128 nodes. A single virtual CI network supports up to 256 storage elements.

For more details on CI configuration follow this link.

To create a CHARON-VAX CI cluster, both of the following elements must be configured:

1. "CIXCD" host adapter

2. "HSJ50" storage controller

CI hardware topology is emulated by establishing TCP/IP channels between the emulated CIXCD host adapters of each CHARON VM. The emulated HSJ50 storage controllers are then connected to every CIXCD host adapter in the virtual CI network.

Cluster operations require that (virtual) disks are simultaneously accessible by all CHARON VMs involved. This can be implemented, for instance, by using a properly configured iSCSI initiator / target structure or a fiber channel storage back-end. Disks on a multiport SCSI switch are not acceptable - because a SCSI switch does not provide true simultaneous access to multiple nodes. 

In this example, setting up two CHARON VMs, two host machines, preferably running the same version of Windows, are required.

Assume that these host systems have network host names CASTOR and POLLUX in the host TCP/IP network.

The following are CHARON VM configuration files for the emulated VAX 6610 nodes running on CASTOR and POLLUX:

Let's review both configurations step-by-step.

1. The first two lines of both configuration files load and establish parameters for the  "PAA" CIXCD host adapter. Only 3 CIXCD parameters are important for us in this situation:  

   Thus, CASTOR connects to POLLUX's port 11021 and listens for POLLUX's connection on port 11012,  POLLUX connects to CASTOR's port 11012 and listens for CASTOR's connection on port 11021 

    

2. The third and fourth lines of both configuration file "DISKS" HSJ50 storage controller and its parameters:

3. The next lines demonstrate the mapping of the "DISKS" HSJ50 storage controller to the disk images, shared between both hosts. A "container" parameter is used for this purpose. This example assumes that all disk images are accessible from both host machines via a network share or some other realization.

In this example we assume that all three host systems have an iSCSI initiator and are connected to a common iSCSI server. The iSCSI disk server provides 8 virtual disks with R/W access on all hosts. These disks are configured as "\\.\PhysicalDrive0" ... "\\.\PhysicalDrive7" on each of the host machines.

The storage configuration must be identical on all three nodes, it is recommended to describe the storage structure in a separate configuration file to be included in each CHARON VM configuration file with the "include" instruction (in this example the name of the configuration file set to "disksets.cfg") and store it on a common network share ("\\DiskServer\Share"):