- Description of why I don't need directio, quickio, or ODM. The 2 main benefits that cames out of using directio was reducing memory consumption by avoiding the page cache AND bypassing the UFS single writer behavior.
ZFS does not have the single writer lock. As for memory, the UFS code path would I/O straight from user buffer to disk overwritting live data. So we won't do this. ZFS will hold the data in memory for the time it takes to insure data-integrity. ZFS concurrent O_DSYNC writes will gang together in the ZIL (ZFS intent log) and be released after the I/Os are done to the log. Performance characteristics will be different between the Filesystems and certainly dynamic data from real workloads, as you point out, will be enlightening. -r _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
