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When suitable storage pools have been established, storage may be allocated in the form of volumes that will be presented to the database hosts.
ASM will consume these volumes as ASM disks, or they may be used to create VMFS datastores under VMware from which will be created VMDK virtual disks that ASM will consume as ASM disks. Additionally, creating filesystems and deploying non-RAC databases on these filesystems is an option.
The volume creation wizard provided by the ScaleIO GUI interface allows the user to specify the volume name, size, storage pool in which to create the volume, whether the new volume should use a RAM Read Cache (if available at the pool level), and whether the new volume should be thick or thin provisioned.
Note: There is a small performance overhead associated with thinly provisioned volumes especially on spinning disks. With solid state storage, this overhead is more than offset by the capacity management advantage of thin provisioning.
Consistency groups allow multiple volumes to be grouped together into a single logical entity when snapshotting.
Existing volumes may be added to a consistency group, or the consistency group may be created with all new volumes.
All ASM disks in a single ASM diskgroup or VMFS datastore should belong to the same consistency group. This allows ScaleIO to make storage crash-consistent snapshots of ASM diskgroups which can then be re-provisioned to secondary hosts.