ZFS is a combined file system and logical volume manager designed to protect against data corruption and support high storage capacities. OpenZFS provides a transparent compression feature that compresses data before storing it and decompresses the data before returning it to the application. This compression not only saves space, but with high performance compressors, can reduce read and write latency by reducing the total volume of data.
OpenZFS offered two main compression options, LZ4 (high speed, low savings) and gzip (low speed, high savings). Today the compression that can be expected would be on the order of 1.1 to 2.0 times.
Integrating ZStd compression, which provides a medium speed, high savings compression algorithm, into OpenZFS will provide additional space savings with a minimal impact on performance. Expected compression with ZStd ranges between 1.1 to 3.6 times.
This project will update and enhance Allan Jude’s original prototype implementation in collaboration with other OpenZFS developers, to prepare it for merging into OpenZFS proper. Work will also include additional tests, backwards compatibility improvements, documentation, and performance analysis. The project is expected to be complete in early fall, 2020.