I have a Dell T30 with two ZFS pools. The first is a mirrored pool (rpool) of two S3700's created on install. This has the host OS and also my VMs/containers. The other pool consists of four 8TB hard drives setup basically as RAID10 in mirrored pairs. For KVMs, I run Windows 10 and Debian 9. Debian runs Docker with a bunch of Usenet stuff, UNMS, my test lab for Home Automation (use a dedicated NUC for the actual home automation setup), etc. I also play around with different Linux builds (Mint, Ubuntu, etc.) periodically. For containers, I have one for Plex and another that is just a file server. Nothing crazy for work load. Plenty of RAM as well. On the hard drives, I just store bulk files. Mainly my media for Plex and backups from other computers. I managed to snag a 16GB Optane NVMe module and a PCI to NVMe adapter for really cheap. I understand I don't really need it, but I got a good deal on it. If I install this, which pool would benefit the most with a SLOG device? The main pool, rpool, has pretty fast drives already. Pveperf shows about 4000+ fsyncs/sec The hard drive pool is obviously slower and shows about 300 fsyncs/sec I don't really do a lot of synchronous writes (the fact that my hard drives are an NFS destination for a few machines as a backup is probably it), but would like to utilize the Optane module. Which pool would show more benefit?