Overview

Challenges

Containers are growing in popularity. Many enterprises choose to build their own Kubernetes clusters. However, the O&M workload of on-premises clusters is heavy, and O&M personnel need to configure the management systems and monitoring solutions by themselves. For enterprises, managing a large number of images requires high O&M, labor, and management costs, and the efficiency is low.

SoftWare Repository for Container (SWR) manages container images that function on multiple architectures, such as Linux and Arm. Enterprises can migrate their image repositories to SWR to reduce costs.

This section describes four ways to migrate image repositories to SWR smoothly. You can select one as needed.

Migration Solutions

**Table 1** Comparison of migration solutions and application scenarios
Solution	Application Scenario	Precautions
Migrating images to SWR using Docker commands	Small quantity of images	Disk storage leads to the timely deletion of local images and time-cost flushing. Docker daemon strictly restricts the number of concurrent pull/push operations, so high-concurrency synchronization cannot be performed. Scripts are complex because HTTP APIs are needed to perform the operations that cannot be implemented through Docker CLI.
Migrating images to SWR using image-syncer	A large number of images	Images can be synchronized from multiple source repositories to multiple destination repositories. Docker Registry V2-based image repositories (such as Docker Hub, Quay, and Harbor) can be migrated to SWR. Memory- and network-dependent synchronization is fast. A file records the blob information about synchronized images to avoid repeated synchronization. You can modify the number of concurrent synchronization tasks in a configuration file. Automatic retry of failed synchronization tasks can resolve most image synchronization issues caused by network jitters. Docker or other programs are not required.
Migrating images to SWR using image-migrator	A large number of images	Images are migrated from a Docker registry built on Docker Registry v2 to SWR.
Synchronizing images across clouds from Harbor to SWR	A customer deploys services in multiple clouds and uses Harbor as their image repository.	Only Harbor v1.10.5 and later versions are supported.