External Monitoring

The External Monitoring tab displays the VM performance data, such as the CPU, memory, disk I/O, and NIC data, obtained from a host by using a libvirt. These data is displayed dynamically in real time through graphs.

CPU

You can select a time span to view the real-time CPU utilization of a VM instance.
  • Available time spans: 15 minutes, 1 hour, 6 hours, 1 day, 1 week, 1 month, 1 year, and custom.
  • Monitoring object:
    • Select All: Display the average, real-time utilization of all CPUs of a VM instance and the utilization of a single CPU.
    • Average: Display the average, real-time utilization of all CPUs of a VM instance.
    • Single CPU: Display the real-time utilization of a single CPU, such as CPU No. 1, No.2, and No. 3.
Figure 1. CPU Real-Time Monitoring


Memory

You can select a time span to view the real-time memory utilization of a VM instance.
  • Available time spans: 15 minutes, 1 hour, 6 hours, 1 day, 1 week, 1 month, 1 year, and custom.
  • Monitoring object:
    • By default, both the used memory and the free memory are displayed.
    • used: Display the used memory of the VM instance.
    • free: Display the free memory of the VM instance.
Figure 2. Memory Real-Time Monitoring


Note:
You can also monitor the real-time usage of the VM memory by using the virsh dommemstat command provided by libvirt.
# Obtain the ID of the VM instance.
[root@localhost ~]# virsh list
 Id    Name                         State
----------------------------------------------------
 1     fe3790c408204c9998ccd6b54272fab1 running

# Obtain the real-time memory utilization of the VM instance. Unit: KB.
[root@localhost ~]# virsh dommemstat 1
actual 2097152
swap_in 0
swap_out 16
major_fault 698
minor_fault 686260
unused 23876
available 2048544
rss 2147224
Note: For memory data, internal monitoring is more accurate than external monitoring. We recommend that you use internal monitoring to monitor the memory data.

Disk I/O

You can select a time span to view the real-time disk I/O of a VM instance.
  • Available time spans: 15 minutes, 1 hour, 6 hours, 1 day, 1 week, 1 month, 1 year, and custom.
  • Monitoring metrics:
    • Disk Read Octets: The read speed of a disk.
    • Disk Read Operations: The read I/O operations per second (IOPS) of a disk.
    • Disk Write Octets: The write speed of a disk.
    • Disk Write Operations: The write I/O operations per second (IOPS) of a disk.
  • Monitoring object:
    • Select All: Display the real-time status of all disk partitions.
    • Single disk partition: Display the real-time read/write status of a single disk partition, such as the vda partition.
Figure 3. Disk I/O Real-Time Monitoring


NIC

You can select a time span to view the real-time NIC status of a VM instance.
  • Available time spans: 15 minutes, 1 hour, 6 hours, 1 day, 1 week, 1 month, 1 year, and custom.
  • Monitoring metrics:
    • Network In Bytes: The speed of receiving NIC packets.
    • Network Packets In: The rate of incoming NIC packets.
    • Network In Errors: The rate of incoming packet errors.
    • Network Out Bytes: The speed of sending NIC packets.
    • Network Packets Out: The rate of outgoing NIC packets.
    • Network Out Errors: The rate of outgoing packet errors.
  • Monitoring object:
    • Select All: Display the utilization of all VM NICs.
    • Single NIC: Display the real-time downstream and upstream rate of the single VM NIC, such as vnic7.0.
Figure 4. NIC Real-Time Monitoring