ZFS threads?

[Ivan Voras]

A VM running 8.0-RC1 with ZFS has load average of 18 while doing rsync 
to it.

I notice there are two sets of 8 ZFS kernel threads present on the 
system, which look like might be the cause of the high load. Is there a 
way to reduce the number of these worker threads?


     0 root            -16    0     0K   280K -       11:47  3.96% 
{spa_zio_6}
     0 root            -16    0     0K   280K -       12:34  0.00% 
{spa_zio_5}
     0 root            -16    0     0K   280K -       12:11  0.00% 
{spa_zio_3}
     0 root            -16    0     0K   280K -       11:43  0.00% 
{spa_zio_1}
     0 root            -16    0     0K   280K -       11:24  0.00% 
{spa_zio_0}
     0 root            -16    0     0K   280K -       11:20  0.00% 
{spa_zio_7}
     0 root            -16    0     0K   280K -       11:19  0.00% 
{spa_zio_2}
     0 root            -16    0     0K   280K -       10:54  0.00% 
{spa_zio_4}
     4 root             -8    -     0K     8K -        3:10  0.00% [g_down]
     0 root            -16    0     0K   280K -        2:49  0.00% {spa_zio}
    12 root            -40    -     0K   128K WAIT     1:31  0.00% 
{swi2: cambio}
    12 root            -64    -     0K   128K WAIT     0:42  0.00% 
{irq17: mpt0}
     0 root            -16    0     0K   280K -        0:38  0.00% 
{spa_zio_7}
     0 root            -16    0     0K   280K -        0:38  0.00% 
{spa_zio_3}
     0 root            -16    0     0K   280K -        0:38  0.00% 
{spa_zio_6}
     0 root            -16    0     0K   280K -        0:38  0.00% 
{spa_zio_1}
     0 root            -16    0     0K   280K -        0:38  0.00% 
{spa_zio_5}
     0 root            -16    0     0K   280K -        0:38  0.00% 
{spa_zio_0}
     0 root            -16    0     0K   280K -        0:38  0.00% 
{spa_zio_2}
     0 root            -16    0     0K   280K -        0:38  0.00% 
{spa_zio_4}