On Tue, 2006-06-27 at 04:19, Mika Borner wrote: > I'm thinking about a ZFS version of this task. Requirements: the > production database should not suffer from performance degradation, > whilst running the clone in parallel. As ZFS does not clone all the > blocks, I wonder how much the procution database will suffer from > sharing most of the data with the clone (concurrent access vs. caching)
given that zfs always does copy-on-write for any updates, it's not clear why this would necessarily degrade performance.. > Maybe we need a feature in ZFS to do a full clone (speak: copy all > blocks) inside the pool, if performance is an issue.... just like the > "Quick Copy" vs. "Shadow Image" -features on HDS Arrays... Seems to me that the main reason you'd need to do a full copy would be to get clone and production on different sets of disks so their access patterns don't end up fighting. For ZFS that requires having separate pools; if they're in the same pool, sharing the unchanged blocks should only help performance. If you want a full copy you can use zfs send/zfs receive -- either within the same pool or between two different pools. _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
