On Wed, Jan 22, 2025 at 08:19:12AM -0500, Theodore Ts'o wrote: > ... but out of place writes means that every single fdatasync() called > by the database now requires a file system level transaction commits. Yes. > So now every single fdatasync(2) results in the data blocks getting > written out to a new location on disk (this is what out of place > writes mean), followed by a CACHE FLUSH, followed by the metadata > updates to point at the new location on the disk, first written to the > file system tranaction log, followed by the fs commit block, followed > by a *second* CACHE FLUSH command. Or you put the compressed data in the log and have a single FUA write.
