MMT architecture

The Mirantis Migration Tool is designed to work with MSR-based source registries.

The mmt command syntax is as follows:

mmt <command> <command-mode> --storage-mode <storage-mode> ... <directory>

The <command> argument represents the particular stage of the migration process:

Migration stage

Description

verify

Verification of the MSR 2.9.x source system configuration. The verify command must be run on the source MSR 2.9.x system. Refer to Verify the source system configuration for more information.

estimate

Estimation of the number of images and the amount of metadata to migrate. The estimate command must be run on the source MSR 2.9.x system. Refer to Estimate the migration for more information.

extract

Extraction of metadata, storage configuration, and blob storage in the case of the copy storage mode, from the source registry. The extract command must be run on the source MSR 2.9.x system. Refer to Extract the data for more information.

transform

Transformation of metadata from the source registry for use with MSR 3.0.x. The transform command must be run on the target MSR 3.0.x system. Refer to Transform the data extract for more information.

restore

Restoration of transformed metadata, storage configuration, and blob storage in the case of the copy storage mode, is made onto the target 3.0.x environment. The restore command must be run on the target MSR 3.0.x system. Refer to Restore the data extract for more information.

The <command-mode> argument indicates the mode in which the command is to run specific to the targeted source registry. mmt is currently the only accepted value, as MMT currently only supports the migration of MSR 2.9.x registries.

The --storage-mode flag and its accompanying <storage-mode> argument indicate the storage mode to use in migrating the registry blob storage.

Storage mode

Description

inplace

The binary image data remains in its original location, leaving the MSR 3.0.x system to connect to the MSR 2.9.x storage location.

Important

Due to its ability to handle large amounts of data, Mirantis recommends the use of inplace storage mode for most migration scenarios.

copy

The binary image data is copied from the source system to a local directory on the workstation that is running MMT. This mode allows movement from one storage location to another. It is especially useful in air-gapped environments.

The <directory> argument is used to share state across each command. The resulting directory is typically the destination for the data that is extacted from the source registry, which then serves as the source for the extracted data in subsequent commands.