A VMFS (Virtual Machine File System) datastore provides shared storage to VMs and a vast majority of organizations are still running their Oracle databases on VMFS datastores. When multiple Oracle databases share the same datastore, it makes monitoring and troubleshooting I/O performance at the array level very difficult. With VMFS, we do not get virtual disk level visibility on the FlashArray™. On the FlashArray, the granularity of array operations like snapshots and replication are at the volume level (i.e. at a VMFS datastore level). That makes it difficult to snapshot a VM, or an individual disk inside a VM, without having to snapshot the entire datastore. Consequently, as datastores scale to tens or hundreds of VMs, it becomes unnecessarily inefficient and complicated to perform day 2 operations like Oracle database backups, cloning and refreshes.
Moreover, VM snapshots are known to suffer from long freezes of the VM when old snapshots are deleted (please refer to VMware KB 1002836 for more details).
VMware Virtual Volumes (vVols) is a new technology introduced in vSphere 6.0 to radically simplify storage management for vSphere admins as well as storage admins. It addresses these issues by providing disk-level granularity and visibility inside the FlashArray. VVols are currently not supported with NVMe-oF, ActiveCluster or ActiveDR. If you are not using these features, you should seriously consider migrating your Oracle database from VMFS to vVols. And as we shall see in the next section, the migration can be done live just with a few clicks.
If you are interested in learning how to migrate an Oracle Database from a physical host to a VMware VM on a vVols datastore, please refer to Virtualize an Oracle Database on VMware using Virtual Volumes .
Migrate VMFS to vVols
vVols are completely integrated with the VMware stack. As a result, we can leverage Storage vMotion to migrate VM disks of an Oracle database from a VMFS datastore to vVols. Storage vMotion is a VMware feature that enables migration of virtual machine disk files between datastores, all while the virtual machine is running. There is no need to schedule a downtime.
Furthermore, the source and the target datastores can even be on different FlashArrays. The host on which the virtual machine is running must have access to both the source and target datastores.
In the following example, we will migrate a VM called lnx-vmfs-demoprd-01 from VMFS to vVols. These steps assume that a vVol datastore has already been configured. If it hasn't been set up, please refer to Virtual Volumes Quick Start Guide for instructions.
1. Verify that the VM disks are on a VMFS datastore
Go to the VM details page and click on the Datastores tab.
2. Invoke the Migrate Wizard
3. Select storage migration option
4. Select target vVol datastore
5. Submit Migration task
Depending on the size of the disks that need to be migrated, the storage migration task will take a little while to complete. When it is done, the Datastores tab for the VM can be checked to verify that VMFS datastore has been replaced with a vVols datastore.
The previous section demonstrated how storage vMotion can be leveraged to easily migrate an Oracle database from VMFS to vVols without any disruption or downtime.