ZFS Deduplication and Compression
Q: Is deduplication of ZFS negativly affected by putting compressed files on it?
A: Yes. Tested by putting similar files (files that well dedup) on a volume in compressed format (RAR5) and completely uncompressed the files from the archives. Maybe different on other compression algorithms?
Data:
| compressed | |
| raw (vm) | 136 GB |
| vol (hypervisor) | 136 GB (no compression as data already compressed) |
| zvol (hypervisor) | 103,4 GB (light deduplication) |
| uncompressed | |
| raw (vm) | 297 GB |
| vol (hypervisor) | 248 GB (hv compression) |
| zvol (hypervisor) | 59,7 GB (massive deduplication) |