The new experimental setting enabletgzbackups allows backups to be
created so that the internal format for .mbz files is .tar.gz.
Restore transparently supports .mbz files with either internal
formats (.zip or .tar.gz).
The .tar.gz format has the following benefits for backup:
- Supports larger files (no limit on total size, 8GB on single file
vs. 4GB limit on total size)
- Compresses text better, resulting in smaller .mbz files.
- Reports progress regularly during compression of single files,
reducing the chance of timeouts during backups that include a
very large file.
Time performance may also be improved although I haven't done a
direct comparison.
When we import courses or duplicate activities, the deduplicating nature of
the file_storage system means that we don't actually have to include the
real files in the backup - just their metadata from the file table.
The restoration process needs to know not to expect files from the backup
phase so a flag is set in moodle_backup metadata.
This commits cleans some code (settings and dependencies)
and one file included previous by error.
Also it disables all the IMS-CC export feature by default, being
possible to enable it under demand by setting (@ config.php):
$CFG->enablebackupconverters = true;
These are David's changes of Mark's code that replace the
plan/tasks/steps infrastructure with a bit simpler one. The changes will
be described in the next commit that will actually finish the
conversion.
TODO: refactor backup/converter/moodle1/stepslib.php into conversion
handlers.
* Several base_converter methods made protected when there was no obvious
reason why they should be public (subject of eventual change still).
* The conversion chain now constructed in advance before any converter
class is instantiated, using Dijkstra's algorithm.
