> Thanks for the responses guys. It looks like I'll probably use RaidZ2 > with 8 drives. The write bandwidth isn't that great as it'll be a > hundred gigs every couple weeks but in a bulk load type of environment. > So, not a major issue. Testing with 8 drives in a raidz2 easily > saturated a GigE connection on the client and the server side. We'll > probably link aggregate two GigE ports onto the switch to boost the > incoming bandwidth. > > In response to some of the other questions - drives are SATA drives > 7200. All connected via a SAS expander backplane onto a machine. CPU > cycles obviously aren't an issue on a Xeon machine/24Gig memory. We > considered a SSD ZIL as well but from my understanding it won't help > much on sequential bulk writes but really helps on random writes (to > sequence going to disk better). Also, doubt L2ARC/ARC will help that > much for sequential either. I could be wrong on both counts here so > please correct me if I'm wrong.
I believe you're correct on all points. The one comment I want to add, as a tangent, is about link aggregation. You may already know this, but a lot of people don't, so please forgive me if I'm saying something obvious. When you aggregate links together, say, 4x 1Gb ports, you are of course increasing the speed & reliability of the network interface, but you don't get something like a 4Gb port. Instead, you get a link where any one client TCP or whatever connection will max out at 1Gb, but the advantage is, while one client is maxing out at 1Gb, another client can come along and also max out another 1Gb, and a 3rd client ... and a 4th client ... Make sense? Obvious? _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
