On Tue, 19 Oct 2010, Gil Vidals wrote:
What would the performance impact be of splitting up a 64 GB SSD into four partitions of 16 GB each versus having the entire SSD dedicated to each pool?
Ignore Edward Ned Harvey's response because he answered the wrong question.
For a L2ARC device, the fill rate (write rate) is carefully limited to a relatively low rate so that it does not constrict reads. If you partition a physical device into four partitions, then you will have increased the actual maximum fill rate by a factor of four, which might impact read performance under heavy load since SSDs are not as good at writing as they are for reading. It is difficult to imagine a performance advantage from partitioning a SSD which is used as a L2ARC. There can only be more overhead associated with needing to manage more logical devices. If there is a hardware failure, it would make understanding the problem a bit more complex. A 1:1 mapping between zfs devices and actual hardware makes things much easier to manage.
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
