Hi, Note that these are page cache rates and that if the application pushes harder and exposes the supporting device rates there is another world of performance to be observed. This is where ZFS gets to be a challenge as the relationship between the application level I/O and the pool level is very hard to predict. For example the COW may or may not have to read old data for a small I/O update operation, and a large portion of the pool vdev capability can be spent on this kind of overhead. Also, on read, if the pattern is random, you may or may not receive any benefit from the 32 KB to 128 KB reads on each disk of the pool vdev on behalf of a small read, say 8 KB by the application, again lots of overhead potential. I am not complaining, ZFS is great, I’m a fan, but you definitely have your work cut out for you if you want to predict its ability to scale for any given workload.
Cheers, Dave (the ORtera man) This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
