Hi! If I understand mount(8) (http://man.openbsd.org/mount) right, FFS mounts have a metadata I/O mode and a data I/O mode. By default, metadata is accessed synchronously and data is accessed asynchronously.
"-o sync" will force both to synchronous mode, and "-o softdep" would change the metadata I/O mode to the alternative softdep access mode. What is the optimal sync &/ softdep configuration for minimizing risk of data loss on unexpected reboot, and maximizing overall filesystem I/O speed? By "data loss" I mean in particular filesystem structure issues that could cause fsck(8) hickups and stability issues (e.g. the "/var/log" directory disappearing altogether - I've seen that happen), secondarily that file data content updates not would have stuck on the disk. Either nothing (no "-o" setting), or "-o sync,softdep", or "-o sync", would all look like they'd make sense. (Can you even do "-o sync,softdep", would that serve any purpose?) Will appreciate to learn your thoughts on this one a lot, Thanks, Tinker
