kvm磁盘io优化以及性能测试以及与物理机对比

ubuntu下kvm的磁盘io性能优化步骤

1、virsh shutdown wcltest2

2、virsh edit wcltest2

<driver name='qemu' type='qcow2'/>
      <source file='/kvm-data/kvm/wcltest2_os_disk.qcow2'/>
      <backingStore/>
      <target dev='hda' bus='ide'/>
      <alias name='ide0-0-0'/>
      <address type='drive' controller='0' bus='0' target='0' unit='0'/>

 磁盘优化：

<driver name='qemu' type='qcow2' cache='none' io='native'/>
<target dev='vda' bus='virtio'/>
 同时删除
<address type='drive' controller='0' bus='0' target='0' unit='0'/>

3、ubuntu下安装sysbench1.0

wget https://github.com/akopytov/sysbench/archive/1.0.zip -O "sysbench-1.0.zip"
unzip sysbench-1.0.zip
apt-get install automake -y
apt-get install libtool -y
./autogen.sh
./configure --without-mysql
备注（ --without-mysql 不编译测试mysql的相关环境）
make
make install

4、io测试随机读写

sysbench --test=fileio --num-threads=50 --file-total-size=2G --file-test-mode=rndrw prepare  准备测试
sysbench --test=fileio --num-threads=50 --file-total-size=2G --file-test-mode=rndrw run      开始测试
sysbench --test=fileio --num-threads=50 --file-total-size=2G --file-test-mode=rndrw cleanup  清除测试文件

物理机执行结果：

File operations:
    reads/s:                      469.90
    writes/s:                     312.81
    fsyncs/s:                     1000.35Throughput:
    read, MiB/s:                  7.34
    written, MiB/s:               4.89General statistics:
    total time:                          10.1041s
    total number of events:              18024Latency (ms):
         min:                                    0.00
         avg:                                   27.86
         max:                                 1047.11
         95th percentile:                      153.02
         sum:                               502103.21Threads fairness:
    events (avg/stddev):           360.4800/49.51
    execution time (avg/stddev):   10.0421/0.03

 kvm优化前执行结果：File operations:

    reads/s:                      243.34
    writes/s:                     162.23
    fsyncs/s:                     513.40Throughput:
    read, MiB/s:                  3.80
    written, MiB/s:               2.53General statistics:
    total time:                          10.1048s
    total number of events:              9290Latency (ms):
         min:                                    0.00
         avg:                                   54.13
         max:                                  769.09
         95th percentile:                      297.92
         sum:                               502877.36Threads fairness:
    events (avg/stddev):           185.8000/65.60
    execution time (avg/stddev):   10.0575/0.02

 kvm优化后结果：

File operations:
    reads/s:                      438.57
    writes/s:                     289.51
    fsyncs/s:                     911.55Throughput:
    read, MiB/s:                  6.85
    written, MiB/s:               4.52General statistics:
    total time:                          10.1056s
    total number of events:              16577Latency (ms):
         min:                                    0.01
         avg:                                   30.30
         max:                                  311.64
         95th percentile:                      123.28
         sum:                               502289.90Threads fairness:
    events (avg/stddev):           331.5400/28.37
    execution time (avg/stddev):   10.0458/0.02

 结论：

kvm优化的io随机读写性能达到接近物理机的磁盘io性能