| Measurement |
Description |
Measurement Unit |
Interpretation |
| Total_capacity |
Indicates the total capacity of this volume group. |
GB |
For the Total descriptor, this measure will report the total disk capacity of the host across all volume groups. |
| Total_physical_extent_size |
Indicates the total number of physical extents on this volume group |
Number |
For the Total descriptor, this measure will report the total number of physical extents across all volume groups on the XenServer host. |
| Alloc_physical_extent_size |
Indicates the number of physical extents allocated to this volume group. |
Number |
For the Total descriptor, this measure will report the total number of physical extents allocated to all volume groups on the XenServer host. |
| Physical_extent_size |
Indicates the size of the physical extents allocated to this volume group. |
MB |
|
| Used_space |
Indicates the space in this volume group that is used by VMs. |
GB |
For the Total descriptor, this measure will report the total space used across all volume groups on the XenServer host.
A high value indicates excessive utilization of a volume group. If the value of this measure is high for the Total descriptor, it indicates that the usage across volume groups is very high. |
| Disk_usage |
Indicates the percentage of the capacity of this volume group that is currently in use. |
Percent |
Ideally, the value of this measure should be low. A very high value indicates that the volume group is running out of space. Under such circumstances, you may want to check the value of Disk capacity allocated to VMs and the Disk space in use by VMs measures to know what is causing the space erosion - is it due to over-allocation of space to VMs? Or abnormal usage of space by the VMs?
For the Total descriptor, this measure will report the percentage of the total disk capacity across all volume groups that is currently used. If the Total descriptor of this measure reports a high value, it indicates excessive usage of storage space across all volume groups. You can then compare the value of this measure across volume groups to know which volume group is being used excessively. |
| Free_physical_extent_size |
Indicates the number of allocated extents that are still unused by this volume group. |
Number |
For the Total descriptor, this measure will report the total number of unused physical extents in all volume groups on the XenServer host.
Ideally, the value of this measure should be high. |
| Free_space |
Indicates the amount of free space on this volume group. |
GB |
This measure reports the difference between the Total disk capacity measure and the Disk space in use by VMs measure.
Ideally, the value of this measure should be high. A very low value could indicate that one/more vMs are utilizing the allocated disk space excessively. To confirm this, check the value of the Disk space in use by VMs measure; if this value is very high, it indicates that the VMs are eroding disk space.
For the Total descriptor, this measure will report the total disk space that is free across all volume groups, and can be allocated to new VMs. |
| Virtual_size |
Indicates the total disk space in this volume group that has been allocated to all VMs on the host. |
GB |
For the Total descriptor, this measure will report the total space that is allocated to all VMs from all volume groups on the host. |
| Unallocated_vsize |
Indicates the total disk space in this volume group that is yet to be allocated to VMs. |
GB |
For the Total descriptor, this measure will report the sum of the space in all volume groups that is still to be allocated to VMs. |
| Allocated_pct |
Indicates the percentage of disk space in this volume group that has been allocated to VMs. |
Percent |
A very high value for this measure indicates that too much disk space has been allocated to the VMs. In such a situation, the host may not have enough disk space for its own operations, and this may cause the host's performance to deteriorate.
For the Total descriptor, this measure will report the percentage of the total disk space across all volume groups that is allocated to all VMs on the host. If the Total descriptor of this measure reports a high value, it indicates that overall, too much storage space has been allocated to VMs. You can then compare the value of this measure across volume groups to know from which volume group the maximum space has been allocated. |
| Allocated_vspct |
Indicates the percentage of space allocated from this volume group that is used by VMs. |
Percent |
A value close to 100% is a cause for concern, as it indicates that one/more VMs are draining the disk space. If the situation persists or aggravates, VMs will experience a severe space crunch, which can bring all VM operations to a halt. To avoid this, you will have to isolate the VMs that are eroding the allocated disk space, clear unnecessary files from the disks of those VMs, and make additional space. Else, you should allocate more space to such VMs.
For the Total descriptor, this measure will report the percentage of the total space allocations from all volume groups that is currently utilized by all VMs on the host. If the Total descriptor of this measure reports a high value, it indicates that the VMs on the host are consuming too much space that is allocated to them. You can then compare the value of this measure across volume groups to know which volume group is being used excessively. |