Testing the Performance

The VM displays the default cache size before cache size modification and the newly configured size after the modification.

1. Add the qemu:commandline tag to the end of the XML file, and enable the all_vcpus_paused and all_vcpus_prepared trace events.

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   <domain type="kvm" xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'> ... <qemu:commandline> <qemu:arg value='--trace'/> <qemu:arg value="all_vcpus*"/> </qemu:commandline> </domain>

2. Set the console log level to prevent KAE device driver logs from being printed to the serial port.

   1	sysctl -w kernel.printk="4 4 1 7"

3. Optional: Synchronize the local time of the migration source and target.

   1	ntpdate <NTP_server_IP_address>

4. Check whether the time is consistent.

   1	date +%Y-%m-%d\ %H:%M:%S.%3N

5. Set downtime-limit to 100.

   1	virsh migrate-setmaxdowntime <VM_name> 100

6. Compile the test tool.

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   export LD_LIBRARY_PATH=/usr/local/kaezip/lib:$ LD_LIBRARY_PATH cd KAEZlib/test/perftest make

   

   KAEZlib/test/perftest is in the KAE 2.0 source package downloaded in Installing KAE.

7. Optional: Execute the KAE compression task in the VM.

   1	./kaezip_perf -m 6 -l 10240 -n 3000

8. Perform VM live migration on the source physical machine.

   1	virsh migrate --live --unsafe <VM_name> qemu+ssh://<VM_IP_address>/system tcp://<VM_IP_address>

9. After the migration is complete, view the all_vcpus_paused event in the logs of the source machine and the all_vcpus_prepared event in the logs of the target machine, and calculate the downtime of live migration based on the timestamps.
   View the logs.

   1	less /var/log/libvirt/qemu/<VM_name>.log