A first class disk (FCD) provides storage life-cycle management on virtual disks as a disk-as-a service or as EBS-like disk storage that allows you to create and manage disks independently of vSphere virtual machines.
vRealize Automation supports two categories of storage disks – standard disk and first class disk. First class disk functionality is supported for vSphere only. vRealize Automation currently provides first class disk functionality as an API-only capability.
A first class disk has its own life-cycle management capabilities that operate independently from a VM. One way that a first class disk differs from an independent persistent disk, is that you can use a first class disk to create and manage snapshots independent of a VM.
You can create a new vRealize Automation storage profile to support either first class disk capabilities or standard disk capabilities. See Learn more about storage profiles in vRealize Automation and Storage resources in vRealize Automation.
You can also add a Cloud.vSphere.Disk first class disk element in your vRealize Automation cloud templates and deployments to support vSphere first class disks. First class disks that have been data-collected appear on the page.
In vCenter, first class disks are also referred to as Improved Virtual Disks (IVD) or managed virtual disks.
- Create, list, and delete a first class disk.
- Resize a first class disk.
- Attach and detach a first class disk.
- Create and manage first class disk snapshots.
- Convert an existing standard disk to first class disk
- Provisioning VMs from snapshots on a datastore cluster.
- Owning and sharing device-based storage blocks by users and tenants.
- Creating and restoring VM snapshots.
- Attaching storage across multiple VMs and across clusters.
- API documentation for FCD is available in the First Class Disk (FCD) section of the Virtual Disk Development Kit Programming Guide.
- Links to API use case documentation for FCD in vRealize Automation are available on the vRealize Automation API Documentation page for your vRealize Automation release.
Considerations and limitations
- First class disk is available for vSphere VMs only.
- vSphere 6.7 Update 2 or later is required to use first class disks.
- Provisioning first class disks on datastore clusters is not supported.
- Volume multi-attach is not supported for first class disks.
- First class disks with snapshots cannot be resized.
- First class disks with snapshots cannot be deleted.
- First class disk snapshot hierarchy can only be constructed by using the
- The minimum VM hardware version required to attach a first class disk is vmx-13 (ESX 6.5 compatible).
- Cloud zone storage limits that you defined in each project are evaluated when you deploy a cloud template that includes a first class disk, or when you run a day relevant day 2 action. A request might fail if the disk requested exceeds the limits.