Table of Contents
Introduction
This section describes how to configure a CHARON-VAX for a Windows CI cluster.
General description
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.
Configuration steps
To create a CHARON-VAX CI cluster, both of the following elements must be configured:
"CIXCD" host adapter
"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.
It is advisable to start any field test with implementing the cluster examples provided below
Example 1: Dual node CI cluster with 4 shared disks
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:
CASTOR node |
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...
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POLLUX node |
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...
set DISKS scs_system_id=3238746238 mscp_allocation_class=1
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Let's review both configurations step-by-step.
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:
Parameter Description ci_node_id An integer value that specifies the address of the virtual CIXCD host adapter on the virtual CI network.
Possible values range from 0 through 127 (Initially set to 127).
port An integer value that specifies the TCP/IP port number at which the emulated CIXCD host adapter listens for connections from another emulated CIXCD host adapter with a certain CI node id. Possible values range from 1024 through 32767.
host A string value that specifies the TCP/IP host name (and optional TCP/IP port number) to connect to another emulated CIXCD host adapter with certain CI node.
The syntax for the string is “host-name[:port-no]” with possible values for "port-no" in the range from 1024 through 32767.
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
The third and fourth lines of both configuration file "DISKS" HSJ50 storage controller and its parameters:
Parameter Description ci_host A string value that specifies an instance name of the emulated CIXCD host adapter serving the virtual CI network.
If this value is not set, CHARON VM tries to locate the host adapter automatically. This automatic lookup works only if the CHARON VM configuration has exactly one instance of an emulated CIXCD host adapter.
ci_node_id An integer value that specifies the address of the emulated HSJ50 storage controller on a virtual CI network. Possible values are from 0 through 7 (initially set to 0).
scs_system_id A string value that specifies the SCSNODENAME of the emulated HSJ50 storage controller.
The string consists of up to 10 characters. Possible characters are uppercase letters A through Z and the integers 0 through 9.
mscp_allocation_class An integer value that specifies the ALLOCLASS of an emulated HSJ50 storage controller.
Possible values range from 0 through 255 (initially set to 0).
In both configuration files, the data related to the emulated HSJ50 storage controller, the "DISKS" must be identical. Not following this rule can cause data corruption on the (virtual) disks.
- 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.
Example 2: Triple node CI cluster with multiple iSCSI disks
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"):
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CHARON VM configuration file for the emulated VAX 6610 node running on HOST001 is as follows:
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CHARON VM configuration file for the emulated VAX 6610 node running on HOST002 is as follows:
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CHARON VM configuration file for the emulated VAX 6610 node running on HOST003 is as follows:
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