9.2-beta, [zpool] iostat fibbing?

[Daniel Braniss]

hi,
after upgrading to 9.2-betat2 (from 9.1-stable), it seems zpool iostat n is
not giving a real picture. Running iostat gives a different picture.
My suspicion got triggerd by a very repetitive output from zpool iostat:
zpool iostat h 5
               capacity     operations    bandwidth
pool        alloc   free   read  write   read  write
----------  -----  -----  -----  -----  -----  -----
h           26.7T  5.84T      9    214   722K  10.9M
h           26.7T  5.84T     12     60   514K  2.90M
h           26.7T  5.84T      9    214   721K  10.9M
h           26.7T  5.84T      9    214   722K  10.9M
h           26.7T  5.84T      9    214   722K  10.9M
h           26.7T  5.84T      9    214   722K  10.9M
h           26.7T  5.84T      9    214   722K  10.9M
h           26.7T  5.84T      9    214   722K  10.9M
h           26.7T  5.84T      9    214   722K  10.9M
h           26.7T  5.84T      9    214   722K  10.9M
h           26.7T  5.84T      9    214   723K  10.9M

while at the same time:
iostat mfid1 5
       tty           mfid1             cpu
 tin  tout  KB/t tps  MB/s  us ni sy in id
   0    18 53.17 224 11.62   0  0  7  1 92
   0    80 60.16 211 12.38   1  0 10  1 88
   0     9 44.36  97  4.20   1  0 11  1 87
   0    20 34.85 134  4.55   1  0 11  1 87
   0    20 23.67 196  4.52   1  0 10  1 88
   0     9 71.10 159 11.05   1  0 12  1 86
   0     9 51.47  89  4.46   1  0 10  2 88
   0   166 43.40 104  4.41   1  0 10  1 88
   0    12 42.47  99  4.11   1  0 10  1 88
   0    30 57.82 196 11.05   1  0 11  1 87
   0    20 30.07 176  5.18   1  0 14  2 84
   0    20 27.34 171  4.56   1  0 12  2 86
   0    20 26.20 179  4.57   1  0 12  2 86
   0    20 66.01 224 14.42   1  0 12  1 86
   0    20 30.82 145  4.35   1  0  7  1 91
   0    30 29.81 167  4.85   1  0  8  1 90
   0    20 31.50 165  5.08   1  0  9  1 89
   0    20 53.95 253 13.33   1  0 10  2 87
   0    20 29.30 148  4.23   1  0 11  1 88


the 5 sec interval seems to be more of a 'suggestion' :-)
and another thing, hitting ^T usually gives:
load: 4.18  cmd: zpool 32267 [spa_namespace_lock] 58.64r 0.00u 0.01s 0% 3080k