On Sun, Jul 25, 2010 at 8:50 PM, Garrett D'Amore <garr...@nexenta.com> wrote: > On Sun, 2010-07-25 at 17:53 -0400, Saxon, Will wrote: >> >> I think there may be very good reason to use iSCSI, if you're limited >> to gigabit but need to be able to handle higher throughput for a >> single client. I may be wrong, but I believe iSCSI to/from a single >> initiator can take advantage of multiple links in an active-active >> multipath scenario whereas NFS is only going to be able to take >> advantage of 1 link (at least until pNFS). > > There are other ways to get multiple paths. First off, there is IP > multipathing. which offers some of this at the IP layer. There is also > 802.3ad link aggregation (trunking). So you can still get high > performance beyond single link with NFS. (It works with iSCSI too, > btw.)
With both IPMP and link aggregation, each TCP session will go over the same wire. There is no guarantee that load will be evenly balanced between links when there are multiple TCP sessions. As such, any scalability you get using these configurations will be dependent on having a complex enough workload, wise cconfiguration choices, and and a bit of luck. Note that with Sun Trunking there was an option to load balance using a round robin hashing algorithm. When pushing high network loads this may cause performance problems with reassembly. -- Mike Gerdts http://mgerdts.blogspot.com/ _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
