About: -I've read the threads about zfs and databases. Still I'm not 100% convenienced about read performance. Doesn't the fragmentation of the large database files (because of the concept of COW) impact read-performance?
I do need to get back to this thread. The way I am currently looking at this is this: ZFS will perform great at doing the transaction component (say the small (8K) O_DSYNC writes) because the ZIL will aggregate them in fewer larger I/Os and the block allocation will stream them to the surface. On the other hand, read streaming will require a good prefetch code (under review) to get the read performance we want. If the requirements balances random writes and read streaming, then ZFS should be right there with the best FS. If the critical requirement focuses exclusively on read streaming a file that was written randomly and, in addition, the number of spindles is limited then that is not the sweetspot of ZFS. Read performance should still scale with number of spindles. And, if the load can accomodate a reorder, to get top per-spindle read-streaming performance, a cp(1) of the file should do wonders on the layout. -r _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss