You can show basic statistics on resource usage for hosts and instances. For more sophisticated monitoring, see the ceilometer project. You can also use tools, such as Ganglia or Graphite, to gather more detailed data.

The following examples show the host usage statistics for a host called devstack. List the hosts and the nova-related services that run on them:$ nova host-list +-----------+-------------+----------+ | host_name | service | zone | +-----------+-------------+----------+ | devstack | conductor | internal | | devstack | compute | nova | | devstack | cert | internal | | devstack | network | internal | | devstack | scheduler | internal | | devstack | consoleauth | internal | +-----------+-------------+----------+ Get a summary of resource usage of all of the instances running on the host: $ nova host-describe devstack +-----------+----------------------------------+-----+-----------+---------+ | HOST | PROJECT | cpu | memory_mb | disk_gb | +----------+----------------------------------+-----+-----------+---------+ | devstack | (total) | 2 | 4003 | 157 | | devstack | (used_now) | 3 | 5120 | 40 | | devstack | (used_max) | 3 | 4608 | 40 | | devstack | b70d90d65e464582b6b2161cf3603ced | 1 | 512 | 0 | | devstack | 66265572db174a7aa66eba661f58eb9e | 2 | 4096 | 40 | +----------+----------------------------------+-----+-----------+---------+ The cpu column shows the sum of the virtual CPUs for instances running on the host. The memory_mb column shows the sum of the memory (in MB) allocated to the instances that run on the host. The disk_gb column shows the sum of the root and ephemeral disk sizes (in GB) of the instances that run on the host. The row that has the value used_now in the PROJECT column shows the sum of the resources allocated to the instances that run on the host, plus the resources allocated to the virtual machine of the host itself. The row that has the value used_max row in the PROJECT column shows the sum of the resources allocated to the instances that run on the host. These values are computed by using information about the flavors of the instances that run on the hosts. This command does not query the CPU usage, memory usage, or hard disk usage of the physical host.

Get CPU, memory, I/O, and network statistics for an instance. List instances: $ nova list +--------------------------------------+----------------------+--------+------------+-------------+------------------+ | ID | Name | Status | Task State | Power State | Networks | +--------------------------------------+----------------------+--------+------------+-------------+------------------+ | 84c6e57d-a6b1-44b6-81eb-fcb36afd31b5 | myCirrosServer | ACTIVE | None | Running | private=10.0.0.3 | | 8a99547e-7385-4ad1-ae50-4ecfaaad5f42 | myInstanceFromVolume | ACTIVE | None | Running | private=10.0.0.4 | +--------------------------------------+----------------------+--------+------------+-------------+------------------+ Get diagnostic statistics: $ nova diagnostics myCirrosServer +------------------+----------------+ | Property | Value | +------------------+----------------+ | vnet1_rx | 1210744 | | cpu0_time | 19624610000000 | | vda_read | 0 | | vda_write | 0 | | vda_write_req | 0 | | vnet1_tx | 863734 | | vnet1_tx_errors | 0 | | vnet1_rx_drop | 0 | | vnet1_tx_packets | 3855 | | vnet1_tx_drop | 0 | | vnet1_rx_errors | 0 | | memory | 2097152 | | vnet1_rx_packets | 5485 | | vda_read_req | 0 | | vda_errors | -1 | +------------------+----------------+ Get summary statistics for each tenant: $ nova usage-list Usage from 2013-06-25 to 2013-07-24: +----------------------------------+-----------+--------------+-----------+---------------+ | Tenant ID | Instances | RAM MB-Hours | CPU Hours | Disk GB-Hours | +----------------------------------+-----------+--------------+-----------+---------------+ | b70d90d65e464582b6b2161cf3603ced | 1 | 344064.44 | 672.00 | 0.00 | | 66265572db174a7aa66eba661f58eb9e | 3 | 671626.76 | 327.94 | 6558.86 | +----------------------------------+-----------+--------------+-----------+---------------+