Re: FreeBSD UFS & fsync

On Tue, Feb 23, 2021 at 8:46 AM Luca Ferrari <fluca1978(at)gmail(dot)com> 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