On 07/19/12 19:27, Jim Klimov wrote:
However, if the test file was written in 128K blocks and then is rewritten with 64K blocks, then Bob's answer is probably valid - the block would have to be re-read once for the first rewrite of its half; it might be taken from cache for the second half's rewrite (if that comes soon enough), and may be spooled to disk as a couple of 64K blocks or one 128K block (if both changes come soon after each other - within one TXG).
What are the values for zfs_txg_synctime_ms and zfs_txg_timeout on this system (FreeBSD, IIRC)? _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss