Storage Directory Structure
Before you begin to configure Charon-PAR emulator instances and to install guest systems, it is advisable to create a directory structure for storing the data required by Charon-PAR emulator instances and guest systems.
Space required for the guest operating systems:
- Charon-PAR/PA3: a minimum of 10GB
- Charon-PAR/PA9: a minimum of 16GB
The numbers above are just basic guidelines for the minimum operating system installation. The space actually required depends on the individual configuration of the system to be migrated.
The following shows a sample directory structure. A structure similar to this will be used for the rest of the examples in this section:
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The Disk and Tape directories will be used to store emulated logical devices, for example, disk containers.
Please note: each instance of Charon-PAR must be started in a separate directory because certain files (SSTORAGE.DAT, NVOLATILE.DAT, UA_SSTORAGE.DAT, and console.dat) will always be created in the current working directory of the emulator instance. Starting multiple emulator instances in the same directory will lead to errors due to file locking problems.
Ethernet Interface Preparation
Red Hat and CentOS Version 7.x
Even though it is not mandatory, it is good practice to exclude the Ethernet interfaces that will be used by the guest system running on Charon-PAR from being managed by the NetworkManager. This can be done for physical NICs dedicated to the guest operating system, or for virtual bridge and TAP configurations (that allow the host and the guest to share a physical interface).
In a network environment controlled by the NetworkManager, the NetworkManager—if configured accordingly—will create and manage the interface configuration files. This may create conflicts with the requirements of the Charon-PAR guest system. If this is the case, a manual configuration should be considered.
There are several options to prevent such problems:
- If the NetworkManager is not needed for other purposes, you can disable ( commands: # systemctl stop NetworkManager; systemctl disable NetworkManager) and create the initial ifcfg-<interface> files in /etc/sysconfig/network-scripts/ manually.
- If the NetworkManager is required for other purposes,
- make sure it uses the ifcfg-files (plugins=ifcfg-rh must be enabled in section [main] of /etc/NetworkManager/NetworkManager.conf),
- stop the NetworkManager (command: # systemctl stop NetworkManager),
- exclude all interfaces required for the Charon-PAR guest(s) from NetworkManager control by adding the line NM_CONTROLLED=no to the respective ifcfg-<interface> file(s),
- restart the NetworkManager (command: # systemctl start NetworkManager).
Example of a minimal ifcfg-<interface> file in /etc/sysconfig/network-scripts/:
NM_CONTROLLED=no |
Example of a minimal bridge configuration via ifcfg-<interface> files in /etc/sysconfig/network-scripts/:
| Bridge definition | Physical NIC | TAP interface |
|---|---|---|
DEVICE=br_enp0s8 | DEVICE=enp0s8 | DEVICE=tap0_enp0s8 |
Please refer to your host system’s man-pages for additional information about the NetworkManager.
There are other settings required to disable certain off-load functions on interfaces dedicated to a Charon-PAR guest system. These settings are configured in the emulator configuration file and described further down in this document.
Red Hat and CentOS Version 8.x
Starting with CentOS/Red Hat/Oracle Linux 8.x, the network-scripts package has been deprecated and the bridge-utils package is no longer available in the standard repositories. Network management for these Linux versions has been changed to use the NetworkManager capabilities. Network management can be handled via the Gnome GUI or via nmcli commands. Please refer to the documentation of your Red Hat or CentOS version for more information.
The network-scripts package can be installed optionally to maintain the same network management methods as used in Linux version 7. However, there is no guarantee how long the package will still be available.
The following image shows a sample configuration that disables the IPv4 configuration for an interface that is to be dedicated to the emulator using the GNOME network settings.
Also, make sure to include the option Make available to other users in the Details tab:
You can use the following command to disable IPv6 for an interface (enp0s8 in the example):
# sysctl -w net.ipv6.conf.enp0s8.disable_ipv6=1
To make this setting permanent, add it to /etc/sysctl.conf.