ZFS pool with a large number of filesystems

[Wim Lewis]

I'm curious how many ZFS filesystems are reasonable to have on a single machine (in a single zpool). We're contemplating a design in which we'd have tens of thousands, perhaps a couple hundred thousand, filesystems mounted out of the same pool. Before we go too far into investigating this idea: Does anyone have real-world experience doing something like that? Is it a situation that ZFS-on-FreeBSD is engineered to handle with good performance? Is there a rough estimate of the resources consumed per additional filesystem (in terms of kernel VM and disk space)?

Thanks for any insight or advice (even, or especially, if the answer is "that's crazy, don't do that" :) )


Wim Lewis / wiml at omnigroup.com