I've heard a claim that ZFS relies too much on RAM caching, but implements no sort of priorities (indeed, I've seen no knobs to tune those) - so that if the storage box receives many different types of IO requests with different "administrative weights" in the view of admins, it can not really throttle some IOs to boost others, when such IOs have to hit the pool's spindles.
For example, I might want to have corporate webshop-related databases and appservers to be the fastest storage citizens, then some corporate CRM and email, then various lower priority zones and VMs, and at the bottom of the list - backups. AFAIK, now such requests would hit the ARC, then the disks if needed - in no particular order. Well, can the order be made "particular" with current ZFS architecture, i.e. by setting some datasets to have a certain NICEness or another priority mechanism? Thanks for info/ideas, //Jim _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
