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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-users] Big I/O performance difference between dom0 and domU
On Tue, Apr 17, 2007 at 05:57:02PM +0100, Marcin Owsiany wrote:
> On Tue, Apr 17, 2007 at 09:34:10AM -0700, Liang Yang wrote:
> > What is the CPU utilization when you did this I/O performance measurement?
>
> "% CPU" reported by bonnie when writing/reading/random seeking in is
> 6/3/0% in dom0 and 4/2/0% in domU. bonnie was the only thing running
> when performing the test.
>
> > As far I can remember, Bonnie++ does not support using outstanding I/Os.
> > So your target RAID volume may not be saturated, i.e. you did not get the
> > peak performance.
>
> What other benchmarking tool would you suggest?
OK, I ran tiobench, which does a multi-threaded test. The conclusions are
basically the same, there is a HUGE performance drop when moving from dom0 to
domU.
Unit information
================
File size = megabytes
Blk Size = bytes
Rate = megabytes per second
CPU% = percentage of CPU used during the test
Latency = milliseconds
Lat% = percent of requests that took longer than X seconds
CPU Eff = Rate divided by CPU% - throughput per cpu load
======
=
= dom0
=
======
Sequential Reads
File Blk Num Avg
Maximum Lat% Lat% CPU
Identifier Size Size Thr Rate (CPU%) Latency
Latency >2s >10s Eff
---------------------------- ------ ----- --- ------ ------ ---------
----------- -------- -------- -----
2.6.18-4-xen-686 1454 4096 1 59.41 4.243% 0.325
136.06 0.00000 0.00000 1400
2.6.18-4-xen-686 1454 4096 2 55.44 7.004% 0.695
640.86 0.00000 0.00000 792
2.6.18-4-xen-686 1454 4096 4 54.86 14.34% 1.403
1794.06 0.00000 0.00000 382
2.6.18-4-xen-686 1454 4096 8 45.94 20.58% 3.231
4126.18 0.00000 0.00000 223
Random Reads
File Blk Num Avg
Maximum Lat% Lat% CPU
Identifier Size Size Thr Rate (CPU%) Latency
Latency >2s >10s Eff
---------------------------- ------ ----- --- ------ ------ ---------
----------- -------- -------- -----
2.6.18-4-xen-686 1454 4096 1 0.94 0.183% 20.700
262.32 0.00000 0.00000 514
2.6.18-4-xen-686 1454 4096 2 1.61 0.049% 23.767
99.26 0.00000 0.00000 3255
2.6.18-4-xen-686 1454 4096 4 2.29 0.328% 32.698
203.58 0.00000 0.00000 698
2.6.18-4-xen-686 1454 4096 8 2.72 0.292% 49.862
574.06 0.00000 0.00000 930
Sequential Writes
File Blk Num Avg
Maximum Lat% Lat% CPU
Identifier Size Size Thr Rate (CPU%) Latency
Latency >2s >10s Eff
---------------------------- ------ ----- --- ------ ------ ---------
----------- -------- -------- -----
2.6.18-4-xen-686 1454 4096 1 10.48 7.397% 1.382
18330.81 0.00243 0.00000 142
2.6.18-4-xen-686 1454 4096 2 10.08 14.59% 2.734
41922.34 0.00994 0.00027 69
2.6.18-4-xen-686 1454 4096 4 9.74 28.07% 5.620
108145.49 0.04493 0.00351 35
2.6.18-4-xen-686 1454 4096 8 9.56 53.08% 10.883
105600.05 0.13138 0.00675 18
Random Writes
File Blk Num Avg
Maximum Lat% Lat% CPU
Identifier Size Size Thr Rate (CPU%) Latency
Latency >2s >10s Eff
---------------------------- ------ ----- --- ------ ------ ---------
----------- -------- -------- -----
2.6.18-4-xen-686 1454 4096 1 1.23 0.819% 0.108
0.55 0.00000 0.00000 150
2.6.18-4-xen-686 1454 4096 2 1.24 1.258% 0.125
40.93 0.00000 0.00000 99
2.6.18-4-xen-686 1454 4096 4 1.22 1.970% 0.125
74.78 0.00000 0.00000 62
2.6.18-4-xen-686 1454 4096 8 1.12 3.463% 0.107
1.53 0.00000 0.00000 32
======
=
= domU
=
======
Sequential Reads
File Blk Num Avg
Maximum Lat% Lat% CPU
Identifier Size Size Thr Rate (CPU%) Latency
Latency >2s >10s Eff
---------------------------- ------ ----- --- ------ ------ ---------
----------- -------- -------- -----
2.6.18-4-xen-686 1016 4096 1 47.22 2.435% 0.410
107.34 0.00000 0.00000 1939
2.6.18-4-xen-686 1016 4096 2 50.51 6.466% 0.768
149.37 0.00000 0.00000 781
2.6.18-4-xen-686 1016 4096 4 34.17 6.062% 2.270
324.78 0.00000 0.00000 564
2.6.18-4-xen-686 1016 4096 8 30.68 10.90% 5.011
843.47 0.00000 0.00000 281
Random Reads
File Blk Num Avg
Maximum Lat% Lat% CPU
Identifier Size Size Thr Rate (CPU%) Latency
Latency >2s >10s Eff
---------------------------- ------ ----- --- ------ ------ ---------
----------- -------- -------- -----
2.6.18-4-xen-686 1016 4096 1 1.39 0.021% 14.048
68.12 0.00000 0.00000 6510
2.6.18-4-xen-686 1016 4096 2 1.42 0.029% 27.293
107.90 0.00000 0.00000 4883
2.6.18-4-xen-686 1016 4096 4 2.86 0.351% 26.259
210.81 0.00000 0.00000 814
2.6.18-4-xen-686 1016 4096 8 4.08 0.334% 35.834
401.12 0.00000 0.00000 1221
Sequential Writes
File Blk Num Avg
Maximum Lat% Lat% CPU
Identifier Size Size Thr Rate (CPU%) Latency
Latency >2s >10s Eff
---------------------------- ------ ----- --- ------ ------ ---------
----------- -------- -------- -----
2.6.18-4-xen-686 1016 4096 1 6.98 4.370% 2.223
8511.98 0.00000 0.00000 160
2.6.18-4-xen-686 1016 4096 2 6.00 7.388% 4.795
18369.97 0.07612 0.00000 81
2.6.18-4-xen-686 1016 4096 4 5.88 13.93% 9.530
39506.77 0.22645 0.00000 42
2.6.18-4-xen-686 1016 4096 8 5.27 22.37% 16.923
79262.92 0.26606 0.01999 24
Random Writes
File Blk Num Avg
Maximum Lat% Lat% CPU
Identifier Size Size Thr Rate (CPU%) Latency
Latency >2s >10s Eff
---------------------------- ------ ----- --- ------ ------ ---------
----------- -------- -------- -----
2.6.18-4-xen-686 1016 4096 1 1.01 0.524% 0.101
2.45 0.00000 0.00000 193
2.6.18-4-xen-686 1016 4096 2 1.03 0.975% 0.127
85.29 0.00000 0.00000 106
2.6.18-4-xen-686 1016 4096 4 0.98 1.461% 0.102
2.79 0.00000 0.00000 67
2.6.18-4-xen-686 1016 4096 8 0.93 2.610% 0.101
2.49 0.00000 0.00000 36
--
Marcin Owsiany <marcin@xxxxxxxxxx> http://marcin.owsiany.pl/
GnuPG: 1024D/60F41216 FE67 DA2D 0ACA FC5E 3F75 D6F6 3A0D 8AA0 60F4 1216
"Every program in development at MIT expands until it can read mail."
-- Unknown
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