On Thu, 7 Jul 2011, Dave Pooser wrote:
My initial thought was mirror the 40GB SSDs for the ZIL and partition the two 64s; mirror two slices for the rpool and two slices for the L2ARC. If there's a smarter way to do it, suggestions gratefully accepted. My current ZFS storage servers are all built around sustained reads/sustained writes, so tuning the ZIL and L2ARC are still outside my experience.
Since you have been reading this forum for a long time, you should already know that the key issue for zfs will be when zfs writes a transaction group because it tends to freeze during the transaction. Otherwise zfs will perform well. The key will be to tune the maximum TXG group size down to a size that your devices can handle expediently. The tunable for this is zfs_write_limit_override.
For example put something like this in /etc/system: * Set ZFS maximum TXG group size to 2684354560 set zfs:zfs_write_limit_override = 0xa0000000 You could also tune down zfs_vdev_max_pending: * Set device I/O maximum concurrency * http://www.solarisinternals.com/wiki/index.php/ZFS_Evil_Tuning_Guide#Device_I.2FO_Queue_Size_.28I.2FO_Concurrency.29 set zfs:zfs_vdev_max_pending = 5 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
