On Fri, 25 Jul 2008, Brandon High wrote: >> I am not sure if ZFS really has to wait for both sides of a mirror to >> finish, but even if it does, if there are enough VDEVs then ZFS can still >> proceed with writing. > > It would have to wait on an fsync() call, since that won't return > until both halves of the mirror have completed. If the cards you're > using have NVRAM, then they could return faster.
While it is possible that the ZFS implementation does actually wait for both drives to report that the data is written, it only has to know that the data is committed to one drive in order to satisfy the synchronous write expectation. This is not the case for legacy mirrored pairs where the disks are absolutely required to contain the same content at the same logical locations. ZFS does not require that disks in a mirrored pair contain identical content at all times. Bob ====================================== Bob Friesenhahn [EMAIL PROTECTED], http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer, http://www.GraphicsMagick.org/ _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
