7.2 dies in zfs

[Randy Bush]

> Everyone's workloads are different, but the panic is the same every
> time: kmem exhaustion.  i386 with KVA_PAGES or amd64 -- happens on both.
> It's highly dependent upon workload and what the filesystem consists of
> (many files vs. fewer files but larger in size, etc.)

these are measurable.  at least until it crashes.  the suggested memsz
script could, instead of giving what to a naive admin are some cute but
unhepful numbers, suggest values for loader.conf.local.

randy