+.sp
+.ne 2
+.na
+\fBzfs_ddt_data_is_special\fR (int)
+.ad
+.RS 12n
+If enabled, ZFS will place DDT data into the special allocation class.
+.sp
+Default value: \fB1\fR.
+.RE
+
+.sp
+.ne 2
+.na
+\fBzfs_user_indirect_is_special\fR (int)
+.ad
+.RS 12n
+If enabled, ZFS will place user data (both file and zvol) indirect blocks
+into the special allocation class.
+.sp
+Default value: \fB1\fR.
+.RE
+
+.sp
+.ne 2
+.na
+\fBzfs_multihost_history\fR (int)
+.ad
+.RS 12n
+Historical statistics for the last N multihost updates will be available in
+\fB/proc/spl/kstat/zfs/<pool>/multihost\fR
+.sp
+Default value: \fB0\fR.
+.RE
+
+.sp
+.ne 2
+.na
+\fBzfs_multihost_interval\fR (ulong)
+.ad
+.RS 12n
+Used to control the frequency of multihost writes which are performed when the
+\fBmultihost\fR pool property is on. This is one factor used to determine the
+length of the activity check during import.
+.sp
+The multihost write period is \fBzfs_multihost_interval / leaf-vdevs\fR
+milliseconds. On average a multihost write will be issued for each leaf vdev
+every \fBzfs_multihost_interval\fR milliseconds. In practice, the observed
+period can vary with the I/O load and this observed value is the delay which is
+stored in the uberblock.
+.sp
+Default value: \fB1000\fR.
+.RE
+
+.sp
+.ne 2
+.na
+\fBzfs_multihost_import_intervals\fR (uint)
+.ad
+.RS 12n
+Used to control the duration of the activity test on import. Smaller values of
+\fBzfs_multihost_import_intervals\fR will reduce the import time but increase
+the risk of failing to detect an active pool. The total activity check time is
+never allowed to drop below one second.
+.sp
+On import the activity check waits a minimum amount of time determined by
+\fBzfs_multihost_interval * zfs_multihost_import_intervals\fR, or the same
+product computed on the host which last had the pool imported (whichever is
+greater). The activity check time may be further extended if the value of mmp
+delay found in the best uberblock indicates actual multihost updates happened
+at longer intervals than \fBzfs_multihost_interval\fR. A minimum value of
+\fB100ms\fR is enforced.
+.sp
+A value of 0 is ignored and treated as if it was set to 1.
+.sp
+Default value: \fB20\fR.
+.RE
+
+.sp
+.ne 2
+.na
+\fBzfs_multihost_fail_intervals\fR (uint)
+.ad
+.RS 12n
+Controls the behavior of the pool when multihost write failures or delays are
+detected.
+.sp
+When \fBzfs_multihost_fail_intervals = 0\fR, multihost write failures or delays
+are ignored. The failures will still be reported to the ZED which depending on
+its configuration may take action such as suspending the pool or offlining a
+device.
+
+.sp
+When \fBzfs_multihost_fail_intervals > 0\fR, the pool will be suspended if
+\fBzfs_multihost_fail_intervals * zfs_multihost_interval\fR milliseconds pass
+without a successful mmp write. This guarantees the activity test will see
+mmp writes if the pool is imported. A value of 1 is ignored and treated as
+if it was set to 2. This is necessary to prevent the pool from being suspended
+due to normal, small I/O latency variations.
+
+.sp
+Default value: \fB10\fR.
+.RE
+