ffs_truncate3 panics

[Rick Macklem]

Rodney W. Grimes wrote:
[stuff snipped]
>It should be possible to design a set of VM's using bhyve, xen or ones
>favorite hypervisor/virtulization platform to do "more" pNFS testing.
>If you could provide a rought machine set needed to have a functional
>test bed, and what should be done to "test" for problems I think it
>should be possible to get you some addition testers.
Well, I've posted this before, but it is easier now, since the code is in head and the
most recent FreeBSD-12 snapshots.

Short version is in "man pnfsserver".
Longer version is at http://people.freebsd.org/~rmacklem/pnfs-planb-setup.xtx

Two VMs would be the minimum, although 3-5 would be a better setup.
(However, you have to set up the service and then mount it and exercise the
 mount point, like you would any other NFS mount. This can't really be automated
 easily, although I typically do a "make" on something like a kernel source tree
 to exercise it.)

rick