On Fri, Oct 10, 2008 at 01:08:57PM -0400, Eric Sproul wrote: > I'm evaluating a server with some SSDs to test performance with separate ZIL > log devices and L2ARC. I have 2 64GB Mtron MOBI drives that I intend to use > for the OS (ZFS root) as well as the slog and L2ARC. I'll be putting all the > ZFS bits on different slices across the two disks (of course whole disks would > be better but that was too expensive.)
I'd be careful about slicing up the SSDs as IOs to the various slices might interact that will impact performance. > What's the recommended size for the slog? Is it dependent mostly on the > expected I/O load? What formula(s) do you use to estimate the best size? I > know it doesn't need to be all that much, but since I need to work with > slices, I have to come up with a size ahead of time. Our experience has been that 10-18GB is more than suggicient for the log device. That said, it's going to depend on your workload and on the performance characteristics of the device you're using. Adam -- Adam Leventhal, Fishworks http://blogs.sun.com/ahl _______________________________________________ storage-discuss mailing list [email protected] http://mail.opensolaris.org/mailman/listinfo/storage-discuss
