* Wait for gnop devices to disappear after "gnop destroy".
Apparently that process is asynchronous now, or maybe it's just slower
than it used to be. Also, after removing a gnop wait for its pool to
be degraded. That isn't instant.
* The zfsd tests no longer require camcontrol.
This was a harmless oversight from
11ed0a95bf
* Fix the zfsd_degrade_001_pos test for recent zfs versions.
ZFS now rate limits checksum errors to about 20 per second. But
zfsd's threshold for degrading a disk is 50 per minute. So we must
alternately corrupt and scrub the pool to ensure that checksum errors
are generated in multiple 1-second windows, so that zfsd will see
enough of them.
* Fix the zfsd_fault_001_pos test in VMs
And, for that matter, when using NVME or SATA disks. As originally
written, the test used the da driver to inject errors. Rewrite it to
use gnop vdevs. gnop can also inject errors. It works on top of any
disk device, and it's also faster than using da.
MFC after: 2 weeks
Sponsored by: Axcient
Differential Revision: https://reviews.freebsd.org/D39437