Последняя строчка в выводе iostat. Совсем все плохо?
extended device statistics
r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 md/d0
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 md/d1
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 md/d10
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 md/d11
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 md/d20
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 md/d21
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 ramdisk1
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 c0t1d0
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 c0t0d0
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 c3t600508B4001074830000A00003190000d0
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 c3t600508B4001074830000A00003130000d0
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 c3t600508B4001074830000D000003A0000d0
18.0 2.0 487.7 16.0 43.6 0.0 2180.8 1.8 100 4 c3t600508B4001074610000E000001F0000d0