On 20 Nov 07, at 1332, Michael R. Gettes wrote: > I am wondering about the use of fsync() on journal'd file systems > as described below. Shouldn't there be much less use of (or very > little use) of fsync() on these types of systems? Let the journal > layer due its job and not force it within cyrus? This would likely > save a lot of system overhead. fsync() forces the data to be queued to the disk. A journaling filesystem won't usually make any difference, because no one wants to keep an intent log of every 1 byte write, or the 100 overwrites of the same block. If you want every write() to go to disk, immediately, the filesystem layout doesn't really matter: it's just a matter of disk bandwidth. Journalling filesystems are more usually concerned with metadata consistency, so that the filesystem isn't actively corrupt if the music stops at the wrong point in a directory create or something. ian ---- Cyrus Home Page: http://cyrusimap.web.cmu.edu/ Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
