This is an interesting discussion. It appears that there is indeed some work to be done with manipulating spin up/down on subsections of an array, etc.
However, in terms of cost/performance for small systems, it may be simpler to solve this with less programming and more hardware. The cost of a smallish ZFS array is approximately $400 (motherboard, CPU, memory) and possibly less plus the cost of the array storage devices and about one memory controller (perhaps $100) for each set of eight disks over the ones the MB can handle by itself. Instead of dealing with the complexities of spinning up partial arrays, it might make sense to make the smallest, lightest, cheapest possible mini-array that can take care of most file needs, and have a larger zfs backing array that's entirely powered off most of the time. This amounts to extending the cache disk to a cache array system. It would simplify the task of updating caches into a main backing store. It's certainly simple to verify function on something like this. Having done some OS releases in a different life, just the testing to verify that complex file system operations were in fact operating properly instead of 98% properly was a massive chore. -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
