Design Principles

1. meta & data be stored separately

• provide storage adapter that implementation can be change as you want

2. leveled storage by size

• small ones stored into rocksdb(default)
• large ones stored into individual files

3. designed as append-only

• for WORM(aka. write-once-read-many) scenario
• support low-erase-cycle devices
• ref local files without copy

4. compress inside by default

• support snappy(default), lzma, lz4, zip and etc.

5. file deduplication

• same file stores meta only

6. support encryption