On Tue, 28 Jul 2009, Marcelo Leal wrote:
Ok Bob, but i think that is the problem about picket fencing... and so we are talking about commit the sync operations to disk. What i'm seeing is no read activity from disks when the slog is beeing written. The disks are "zero" (no read, no write).
This is an interesting issue. While synchronous writes are requested, what do you expect a read to return? If there is a synchronous write in progress, should readers wait for the write to be persisted in case the write influences the data read?
Note that I am not saying that huge synchronous writes should necessary block reading (particularly if the reads are for unrelated blocks/files), but it is understandable if zfs focuses more on the writes.
Bob -- Bob Friesenhahn bfrie...@simple.dallas.tx.us, 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
