Messing with modern ZFS compression options

ZFS includes inline compression, meaning files are compressed and decompressed on the fly. While you might expect this to reduce IO performance, it’s been proven to improve throughput by reducing the amount of expensive reads required, especially on older spinning drives. Inline compression is wonderful. I don’t need to rotate logs to compressed files. I can temporarily expand virtual disks to raw images without taking up the entire maximum space of the disk. It’s also great for thwarting zipbomb attacks! Save for highly-compressed files like video, I’ve always left the compression algorithm as the default, which for years has been lz4. But I have a few specific datasets for which more aggressive compression can be done. For example, I have one dataset containing my collection of reference PDFs and ebooks I rarely access, and have large blocks of text that are great candidates for lossless compression. I interrogated this dataset holding my books with the requisite zfs commands: # zfs…