Hi all, I'm running a virtual machine with FreeBSD 12.2, PostgreSQL 12.5 and UFS as filesystem. I was experimenting with fsync = off and pgbench, and I see no particular difference in tps having fsync enabled or disabled. Now, the same tiny test on a linux box provides a 10x tps, while on FreeBSD is a 1% increase. I'm trying to figure out why, and I suspect there is something related to how UFS handles writes. Any particular advice about tuning and parameters that can be affecting the "no difference" with fsync turned off? % sudo tunefs -p /dev/gpt/DATA tunefs: POSIX.1e ACLs: (-a) disabled tunefs: NFSv4 ACLs: (-N) disabled tunefs: MAC multilabel: (-l) disabled tunefs: soft updates: (-n) disabled tunefs: soft update journaling: (-j) disabled tunefs: gjournal: (-J) disabled tunefs: trim: (-t) enabled tunefs: maximum blocks per file in a cylinder group: (-e) 8192 tunefs: average file size: (-f) 16384 tunefs: average number of files in a directory: (-s) 64 tunefs: minimum percentage of free space: (-m) 8% tunefs: space to hold for metadata blocks: (-k) 6408 tunefs: optimization preference: (-o) time tunefs: volume label: (-L) DATA
