Pre-requisites for preserving owners and groups on migrated data

Migration Toolkit for Containers (MTC) uses rsync to migrate Persistent Volume data from source cluster to destination cluster. It uses --group & --owner options in rsync to preserve UID/GID bits on files. The files are owned by same users and groups on the destination cluster as the source cluster. This is to ensure that the workloads run correctly in the destination cluster post migration. The goal of this article is to explain how rsync preserves UID/GIDs in MTC....

May 12, 2022 · Pranav Gaikwad

Fixing duplicate UID ranges on OpenShift namespaces after migration

When a Namespace is created in OpenShift, it is assigned a unique User Id (UID) range, a Supplemental Group (GID) range, and unique SELinux MCS labels. They are stored in the metadata.annotations field of the Namespace. Everytime a new Namespace is created, OpenShift assigns it a new range from its available pool of UIDs and updates the metadata.annotations field to reflect the assigned values. However, if the Namespace resource already has those annotations set, OpenShift does not re-assign new values for the Namespace....

January 26, 2022 · Pranav Gaikwad