Monitoring Block Storage for VPC health states, volume status, and metrics

By using the UI, CLI, or API, you can check on the status and health states of your Block Storage for VPC volumes. You can also view the cumulative number of read and write operations for a specific volume that is attached to a virtual server instance.

Monitoring Block Storage for VPC performance

You can monitor certain Block Storage for VPC volume performance from the VPC virtual server instance metrics. These metrics include:

Cumulative number of bytes read for a volume since the virtual server instance was started.
Cumulative number of bytes written for a volume since the virtual server instance was started.

To see these metrics in the UI, do the following.

In the IBM Cloud console, go to VPC Infrastructure > Compute > Virtual server instances.
Click the instance name to go to the instance details.
Click the Monitoring tab and scroll to the Volume metrics.
Select a volume. The read and write metrics are displayed. Figure 1 shows this view.

Figure showing volume metrics. — Figure 1. Read/write metrics for Block Storage for VPC volumes.

Block Storage volume status

The following table shows the statuses that you might see when you create, view, or manage your Block Storage for VPC volumes, and the associated health state.

Table 1. Block Storage statuses
Status	Meaning	Health state
Available	A volume is available and can be attached to an instance. An attached data volume is available. A boot volume is available.	OK
Failed	A volume creation failed.	Inapplicable
Pending	A volume is being created.	Inapplicable
Pending deletion	A volume is being deleted. When you're unsure if the volume is deleted, verify this state. Attempting to delete a volume again while in this state results in a conflict error.	Inapplicable
Updating	A volume's capacity is expanding or volume IOPS being adjusted.	OK
Unusable	A volume is unusable because the customer root key (CRK) was deleted or disabled.	Inapplicable

Block Storage volume health states

Volume health states correspond with volume statuses. Table 2 describes the health states and health reasons.

Table 2. Block Storage health states and reasons
Health State	Reason
OK	A volume is performing at the expected I/O performance and capacity is sufficient. No network connection issues are present. Or the volume was restored from a snapshot (hydration is completed).
Degraded	A volume is experiencing degraded performance for any of the following reasons: Volume data is being restored (hydrated) and the volume shows as degraded until hydration is completed. Volume initialization from a snapshot failed, and the volume hydration failed. Volume hydration is not started. Volume hydration is paused. The snapshot is in an unusable state.
Inapplicable	The volume is being created. The volume creation failed. The volume is pending, pending deletion, or unusable. No health reasons are reported.
Faulted	The volume is unreachable, inoperative, or entirely incapacitated.

For more information about the health states and reason codes in the API, see the API reference for creating, listing, and updating volumes.

Volume performance when you restore from a snapshot

Boot and data volume performance is initially degraded when you restore them from a snapshot. During the restoration, your data is copied from IBM Cloud® Object Storage to Block Storage for VPC. After the restoration process is complete, full IOPS can be realized on the new volume.

Restoring a boot volume from a "bootable" snapshot and then provisioning an instance with it results in slower performance because the restored boot volume is not yet fully hydrated (that is, fully provisioned). Performance is slower than creating an instance from a regular boot volume.