Hi,
I'm running a vserver running various LAMP servers. A while ago I
installed munin to check how the server was behaving at various
times. It turns out that the server has a LOT of iowait (up to 115)
when under load.
What I did was that I ran tiobench on the local HD and this is what I
got:
--
Sequential Reads
File Blk Num
Avg Maximum Lat% Lat% CPU
Identifier Size Size Thr Rate (CPU%)
Latency Latency >2s >10s Eff
---------------------------- ------ ----- --- ------ ------
--------- ----------- -------- -------- -----
2.6.14.3-vs2.0.1 100 4096 1 446.29 99.97%
0.006 0.04 0.00000 0.00000 446
2.6.14.3-vs2.0.1 100 4096 2 728.70 396.4%
0.007 0.05 0.00000 0.00000 184
2.6.14.3-vs2.0.1 100 4096 4 855.43 1587.%
0.011 0.20 0.00000 0.00000 54
2.6.14.3-vs2.0.1 100 4096 8 839.09 2328.%
0.013 56.08 0.00000 0.00000 36
Random Reads
File Blk Num
Avg Maximum Lat% Lat% CPU
Identifier Size Size Thr Rate (CPU%)
Latency Latency >2s >10s Eff
---------------------------- ------ ----- --- ------ ------
--------- ----------- -------- -------- -----
2.6.14.3-vs2.0.1 100 4096 1 418.79 96.48%
0.006 0.02 0.00000 0.00000 434
2.6.14.3-vs2.0.1 100 4096 2 754.47 386.3%
0.006 0.04 0.00000 0.00000 195
2.6.14.3-vs2.0.1 100 4096 4 839.15 1374.%
0.010 0.05 0.00000 0.00000 61
2.6.14.3-vs2.0.1 100 4096 8 739.47 870.8%
0.009 0.04 0.00000 0.00000 85
Sequential Writes
File Blk Num
Avg Maximum Lat% Lat% CPU
Identifier Size Size Thr Rate (CPU%)
Latency Latency >2s >10s Eff
---------------------------- ------ ----- --- ------ ------
--------- ----------- -------- -------- -----
2.6.14.3-vs2.0.1 100 4096 1 6.89 4.602%
0.021 9.83 0.00000 0.00000 150
2.6.14.3-vs2.0.1 100 4096 2 9.12 15.32%
0.031 80.06 0.00000 0.00000 60
2.6.14.3-vs2.0.1 100 4096 4 9.65 52.36%
0.040 0.54 0.00000 0.00000 18
2.6.14.3-vs2.0.1 100 4096 8 9.92 102.5%
0.066 100.08 0.00000 0.00000 10
Random Writes
File Blk Num
Avg Maximum Lat% Lat% CPU
Identifier Size Size Thr Rate (CPU%)
Latency Latency >2s >10s Eff
---------------------------- ------ ----- --- ------ ------
--------- ----------- -------- -------- -----
2.6.14.3-vs2.0.1 100 4096 1 0.34 0.148%
0.010 0.03 0.00000 0.00000 230
2.6.14.3-vs2.0.1 100 4096 2 0.34 0.352%
0.011 0.06 0.00000 0.00000 98
2.6.14.3-vs2.0.1 100 4096 4 0.37 1.033%
0.017 0.07 0.00000 0.00000 36
2.6.14.3-vs2.0.1 100 4096 8 0.38 1.596%
0.016 0.14 0.00000 0.00000 24
--
I'm wondering; shouldn't the CPU % be lower on reads? Is there a way
to increase this performance?
A.
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Received on Mon Aug 28 18:32:25 2006