I want to test the disk IO performance like read, write, random read, random write and so on both in physical machine and VMs (with aufs file system).Also I want to test the throughput performance in a single bare machine and VMs running on the hypervisor to get how much performance loss in Virtual machine (KVM).I used this command before, but it wasn't enough,and it just tested 1 process!(you can see the output here)$ iozone -Mce -I -+r -r 256k -s 2g -f iozone_$i.dat$$ -i0 -i1 -i2What command should I use?
How to test Disk IO on VMs with iozone?
performance;kvm;io;testing;iozone
If you add the -t switch you can specify how many writers you want iozone to make use of. From the IOzone PDF.-t #Run Iozone in a throughput mode. This option allows the user to specify how many threads or processes to have active during the measurement. Example$ ./iozone -i 0 -t 2Children see throughput for  2 initial writers 1=  433194.53 KB/secParent sees throughput for  2 initial writers   =    7372.12 KB/secMin throughput per process          =       0.00 KB/sec Max throughput per process          =  433194.53 KB/secAvg throughput per process          =  216597.27 KB/secMin xfer                    =       0.00 KBChildren see throughput for  2 rewriters    =  459924.70 KB/secParent sees throughput for  2 rewriters     =   13049.40 KB/secMin throughput per process          =  225610.86 KB/sec Max throughput per process          =  234313.84 KB/secAvg throughput per process          =  229962.35 KB/secMin xfer                    =     488.00 KBexcerpt - 10 iozone Examples for Disk I/O Performance Measurement on LinuxTo execute the iozone in throughput mode, use -t option. You should  also specify the number of threads that needs to be active during this  test.The following example will execute the iozone throughput test for  writes using 2 threads. Please note that you cannot combine -a option  with -t option.