On Tue, Feb 23, 2021 at 8:46 AM Luca Ferrari <fluca1978@xxxxxxxxx> wrote: > I'm using sata disks, not scsi. Assuming I'm not looking at the wrong > parameter, I wil attach a scsi disk to do the same test and see if > something changes. I've tested the same version of PostgreSQL, same benchmark, on a scsi disk. However, turning off fsync does not provide any increment at all (something that spans in less than 1% tps). I've checked and I have WCE enabled on such disk, but apparently I cannot modify (I suspect this is due to the virtualization of the disk): # echo "WCE: 0" | camcontrol modepage da0 -m 0x08 -e camcontrol: error sending mode select command # camcontrol modepage da0 -m 0x08 | grep WCE WCE: 1 and the filesystem has everything disabled: # tunefs -p da0p1 tunefs: Can't stat da0p1: No such file or directory 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) disabled tunefs: maximum blocks per file in a cylinder group: (-e) 4096 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) I think I will not be able to test in a virtual environment, unless I'm missing something. Thanks, Luca
