The Avalon 5.x to 6.x migration tool copies and transforms Avalon 5.x's Fedora 3 data to Avalon 6.x's Fedora 4 data. The tool can be run as follows:
bundle exec rake avalon:migrate:repo
When you run the migration in the command line, you can see a broad view of how much progress has been made for each Class. Notice the last line indicates a second pass for Migrating MediaObject. The second pass is necessary to associate master files with media objects and get them ordered properly.
Command Options
| Option | Explanation | Example Usage | Default Value |
|---|---|---|---|
| CONFIRM | Required in order to prevent accidental execution | CONFIRM=yes | |
| pids | A comma separated list of Avalon 5.x Fedora 3 pids to migrate | pids=avalon:1,avalon:2,avalon:3 | |
| pidfile | Path to a filename containing one Avalon 5.x Fedora 3 pid per line | pidfile=/path/to/pidfile |
|
| parallel_processes | Number of parallel processes the migration tool should use | parallel_processes=4 | number of processors - 2 |
| overwrite | Determines whether: existing Fedora 4 objects should be kept, cleaned out, and reused (overwrite=true); or new objects should be created even if matching migrated objects already exist (overwrite=false) | overwrite=true | false |
| namespace | The Fedora 3 namespace that should be migrated | namespace=media | avalon |
Rerunning the migration
Once the migration is running, it is best to let it fully finish before attempting to rerun failed objects. The migration should fail objects that are missing parent or child objects. Once the migration is finished running, a list of the failed object ids can be collected into a file by running this command:
bundle exec rails r 'puts MigrationStatus.where(status: "failed").map(&:f3_pid).uniq.join("\n")' > failed_objects
The migration tool can then be rerun with this list:
bundle exec rake avalon:migrate:repo pidfile=failed_objects
Potential Problems
First read the Migration Report to determine what objects failed migration and why.
| Problem | Workaround |
|---|---|
| Objects fail with errors about mismatched prefixes | Turn off parallel processing by setting parallel_processes=1 |
| Objects fail with LDP conflict | Turn off parallel processing by setting parallel_processes=1 |
| Poster and thumbnail images missing | See script on /wiki/spaces/AVALON/pages/1957954849 |
| Section permalinks incorrect | See script on /wiki/spaces/AVALON/pages/1957954849 |
| Permalink collisions | See script on /wiki/spaces/AVALON/pages/1957954849 |
Helper Scripts
See /wiki/spaces/AVALON/pages/1957954849 for scripts that can be adapted to your institution to help find and fix data issues post-migration.