MIGRATION GUIDE IBM Rational ClearCase to Perforce VCS Migration Guide v2.5, January 31, 2017 This document provides information for planning a migration from a legacy ClearCase VCS system to Perforce VCS. Basic familiarity with ClearCase architecture, concepts, and terminology are helpful, but not strictly necessary, when reading this document. Corresponding Perforce concepts and terminology are introduced. We discuss preliminary planning and review three history import strategies – starting over, detailed history import (DHI), and baseline & branch import (BBI). ClearCase to Perforce migration projects vary greatly in scale and complexity. Small, simple environments with basic migration requirements are typically migrated in about eight business days, including Perforce setup, migration, and training for users and administrators. Large, complex ClearCase environments may perform a series of migrations that occur over the course of a several months or more, as teams migrate at times convenient for them. This document is not intended to be a replacement for an actual assessment of your environment. An assessment would focus on those factors most relevant to your environment and produce a custom migration strategy. MIGRATION GUIDE IBM Rational ClearCase to Perforce SCM Migration Guide | ii 1. Introduction .......................................................................................................................................1 2. Preliminary Migration Preparation.................................................................................................1 2.1. Review Existing Branching Strategy ......................................................................................1 2.2. Perforce Directory Standard (PDS) ........................................................................................1 2.3. Release Processes and the PDS .............................................................................................1 2.4. Perforce Streams .....................................................................................................................2 2.5. Addressing Intellectual Property Concerns .........................................................................2 2.6. Training .....................................................................................................................................2 2.7. Perforce Transition Team ........................................................................................................2 3. Import Strategies ..............................................................................................................................3 3.1. Tips – Starting Over .................................................................................................................3 3.1.1. Starting Over – Pros .......................................................................................................3 3.1.2. Starting Over – Cons ......................................................................................................3 3.2. Detailed History Import ..........................................................................................................3 3.2.1. ClearCase Detailed Import History Preparation ........................................................4 3.2.2. Custom Scripting ...........................................................................................................4 3.2.3. Hardware Capacity Planning ........................................................................................4 3.2.4. Detailed History Import – Pros ......................................................................................4 3.2.5. Detailed History Import – Cons ....................................................................................5 3.3. Baseline & Branch Import .......................................................................................................5 3.3.1. Baseline & Branch Import – Pros ..................................................................................6 3.3.2. Baseline & Branch Import – Cons .................................................................................7 3.3.3. Warnings .........................................................................................................................7 4. Terminology and Concepts .............................................................................................................7 4.1. VOBs and Depots ....................................................................................................................7 4.2. ClearCase Regions ..................................................................................................................7 4.3. VOB Servers vs. “The Server” .................................................................................................8 4.3.1. Operating System Selection .........................................................................................8 4.4. Registry and License Servers .................................................................................................8 4.5. Release Servers and Installation ............................................................................................8 4.6. View Servers, Protecting Unversioned and Checked Out Files .........................................9 4.7. ClearCase MultiSite vs. Perforce Proxies ..............................................................................9 4.8. Replacing ClearCase Views with Perforce Workspaces ......................................................9 4.9. Rethink Label Strategies .......................................................................................................10 4.10. Unified Change Management (UCM) ...............................................................................10 4.11. Migration Technical Details ................................................................................................10 4.11.1. Evil Twins .....................................................................................................................10 4.11.2. Symlinks on Windows ...............................................................................................11 4.11.3. File Type Mappings and Limitations .......................................................................11 Perforce Software 400 N. 1st Avenue, Suite 200 +1 510.864.7400 www.perforce.com Minneapolis, MN 55401 [email protected] Copyright © 2008-2017, Perforce Software. All rights reserved. MIGRATION GUIDE IBM Rational ClearCase to Perforce SCM Migration Guide | 1 • Helps convey branching patterns for 1. Introduction everything Perforce. This document provides information for planning a • Helps intuitively map change propagation paths for the migration from a legacy ClearCase VCS system to Perforce various flows of change (e.g. the life of a bug discovered VCS. Basic familiarity with ClearCase architecture, in maintenance, or the life of a new feature). concepts, and terminology are helpful, but not strictly • Conveys the stage in the life cycle of any particular necessary, when reading this document. Corresponding piece of code: experimental, development, released. Perforce concepts and terminology are introduced. It is a best practice to establish a Perforce Directory Standard We discuss preliminary planning and review three history (PDS) to establish the directory structure and corresponding import strategies – starting over, detailed history import branching strategy in Perforce. A template for developing (DHI), and baseline & branch import (BBI). your own PDS is available for download here. You can participate in discussions about the PDS on the Perforce ClearCase to Perforce migration projects vary greatly in scale Forums here. Contact Perforce Consulting and complexity. Small, simple environments with basic ([email protected]) for further information. migration requirements are typically migrated in about eight business days, including Perforce setup, migration, 2.3. Release Processes and the PDS and training for users and administrators. Large, complex The directory structure in Perforce can be thought of as ClearCase environments may perform a series of migrations “low” and “high” levels. Low levels represent your software that occur over the course of a several months or more, as products, and can vary for each software product. High teams migrate at times convenient for them. levels of a Perforce directory structure convey branching structure, project management, and software lifecycle This document is not intended to be a replacement for an information. A well-designed, high-level directory structure actual assessment of your environment. An assessment is intuitive for developers and lends itself well to project would focus on those factors most relevant to your management metrics, policy enforcement by branch type, environment and produce a custom migration strategy. and automation of various kinds. Migration to Perforce typically involves defining a Perforce 2. Preliminary Migration Preparation Directory Standard (PDS) for each product imported into Perforce, and in some cases for the entire organization. A 2.1. Review Existing Branching Strategy Early in migration planning, determine whether the current PDS encourages consistency in release processes for various branching strategy used in ClearCase, if any, is appropriate software products, but can be as flexible as needed to to use going forward with Perforce. If