Compression seems to be not used in the new storage backend (disk-objectstore)

[zhubonan]

Just migrated my AiiDA installation from 1.6 to 2.0. In my old file-based repository I used gzip to mannally compress many text files, which resulted in a large save in space (600 GB -> 80GB). When I migrate to 2.0 I unzip all files and then do the migration.

After the migration I realized that the migrated storage does not actually compress the files storage, despite that the capability been there in disk-objectstore. For migration this is understandable, since compressing everything would be slow. I can get a compressed repository by creating a new Container and import all data from the migrated Container with compression on.

However, looking at the verdi storage maintain code, it seems that compression is also not turned on when packing loose files:

aiida-core/aiida/repository/backend/disk_object_store.py

Lines 178 to 184 in 5c1eb3f

	with self._container as container:
	if pack_loose:
	files_numb = container.count_objects()['loose']
	files_size = container.get_total_size()['total_size_loose'] * BYTES_TO_MB
	logger.report(f'Packing all loose files ({files_numb} files occupying {files_size} MB) ...')
	if not dry_run:
	container.pack_all_loose()

Sinec in pack_all_loose, compress defaults to False.
https://github.com/aiidateam/disk-objectstore/blob/16e6ff98c904ef0ec8b03ba3ce6e1eb00204c328/disk_objectstore/container.py#L1305-L1310

Should there be an option to have this turned on? Or it is some choice by design?
At the moment, I can still do pack_all_loose with compression via disk-objectstore's interface. But this do mean that a normal AiiDA user would not be benefiting from compression?