vxdmpadm iostat and iostat shows different io rates

utkanbir · *nix forums addict Joined: 18 May 2005 Posts: 73

Hi ,

This is sun solaris , emc raid10 , 1 hba.

I am making a basic file read test :

timex dd if=test of=/dev/null bs=1048576
2000+0 records in
2000+0 records out

real 35.30
user 0.00
sys 0.21

(2gb file)

vxdmpadm iostat show all interval=3 count=100000

cpu usage = 3us per cpu memory = 4096b
OPERATIONS KBYTES AVG
TIME(ms)
PATHNAME READS WRITES READS WRITES READS
WRITES
c1t0d0s2 0 0 0 0 0.000000
0.000000
c2t5006048C48585813d80s2 200 0 204800 0
14.597012 0.000000
c1t3d0s2 0 0 0 0 0.000000
0.000000
c1t1d0s2 0 0 0 0 0.000000
0.000000
c1t5d0s2 0 0 0 0 0.000000
0.000000
c1t2d0s2 0 0 0 0 0.000000
0.000000
c1t4d0s2 0 0 0 0 0.000000
0.000000

iostat -zxcn 3

cpu
us sy wt id
0 0 0 100
extended device statistics
r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device
0.0 16.3 0.0 22.0 0.1 0.2 5.7 13.4 9 9 d1
0.0 16.3 0.0 22.0 0.0 0.2 0.0 12.3 0 8 d11
0.0 16.3 0.0 22.0 0.0 0.2 0.0 10.9 0 8 d12
0.0 22.3 0.0 25.0 0.0 0.2 0.0 11.1 0 10 c1t3d0
0.0 22.3 0.0 25.0 0.0 0.3 0.0 12.7 0 11 c1t0d0
68.7 0.0 70328.6 0.0 0.0 1.0 0.0 14.5 0 99
c2t5006048C48585813d80

Accorrding to the vxdmpadm iostat output , 204800 kb. is read per
second , but iostat says 70mb. read per second. It takes 35sec. to
read this 2gb. file , so 70mb. per read value seems correct. Why does
vxdmpadm differs?

Kind Regards,
tolga

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