On Mon, Feb 22, 2021 at 10:38 PM Thomas Munro <thomas.munro@xxxxxxxxx> wrote: > Do you have WCE enabled? In that case, modern Linux file systems > would do a synchronous SYNCHRONIZE CACHE for our WAL fdatasync(), but > FreeBSD UFS wouldn't as far as I know. It does know how to do that > (there's a BIO_FLUSH operation, also used by ZFS), but as far as I can > see UFS uses it just for its own file system meta-data crash safety > currently (see softdep_synchronize()). (There is also no FUA flag for > O_[D]SYNC writes, an even more modern invention.) Apparently no WCE, but I could be looking at the wrong piece: % sysctl kern.cam.ada | grep write_cache kern.cam.ada.2.write_cache: -1 kern.cam.ada.1.write_cache: -1 kern.cam.ada.0.write_cache: -1 kern.cam.ada.write_cache: -1 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. Or if you have any other suggestion about what to inspect, please advice. Thanks, Luca
