site_archiver@lists.apple.com Delivered-To: darwin-dev@lists.apple.com Thanks, - Reto _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.appl... I'm looking for a way to (1) enable direct IO on OS X (10.4) and (2) a way to write w/o updating metadata (i.e. last access time). All in the context of the ever popular tx log file use case. - are there plans to support O_DIRECT, or mount -o forcedirectio (disable cache)? - are there plans to support the O_DSYNC open flag (avoid some metadata update, i.e. last access time)? To help me understand what is available (what I found at least) in 10.4, I appreciate your help with the following 3 questions: (a) is the sync mount option equivalent to the directio flag, I can e.g. get on Solaris?, or (b) if I open a file with O_SYNC (in fcntl.h but not "man 2 open" page) is this the same as writing to a file on a FS that I mounted with "mount -o sync" ? (c) is writing (write system call) to a "-o sync" mounted FS (HFS+) equivalent to fsync'ing the fd (I only care about a single tx log file), except that I save a system call? I.e. can I be assured that (module the fcntl F_FULLSYNC call) the data is flushed to disk if I write to a "-o sync" HFS, or "D_SYNC" opened file? This email sent to site_archiver@lists.apple.com