kmem_map too small with ZFS and 8.2-RELEASE

[Matthias Gamsjager]

> # Disable ZFS prefetching
> # http://southbrain.com/south/2008/04/the-nightmare-comes-slowly-zfs.html
> # Increases overall speed of ZFS, but when disk flushing/writes occur,
> # system is less responsive (due to extreme disk I/O).
> # NOTE: Systems with 8GB of RAM or more have prefetch enabled by
> # default.
> vfs.zfs.prefetch_disable="1"
>
>
> I wonder if this is still the case since the website you referring to was
from 2008 and I guess a lot has changed since then.
For example I get horrible performance with prefech disabled. (running on 4
disk striped mirror)