A thin clone is a read/write copy of a volume, volume group, file system, or a snapshot of these resource types. In PowerStoreOS 3.0 and later, a NAS server can be cloned. Thin clones are essentially thin copies of the object from which it was created. As with snapshots, thin clones are thin, pointer-based objects that use redirect-on-write technology that provides immediate access to the data contained in the source of the thin clone. Thin clones are not full copies of the original source and because they share data blocks with the parent resource, they should not be used for disaster recovery scenarios. Figure 34 shows an example of a thin clone that is created from a supported resource. When initially created, the thin clone shares all blocks with the resource from which it was created. Due to redirect-on-write technology, as new writes to the original resource or the thin clone are made, new space is consumed, and original data remains until it is no longer in use.

Figure 34.    Thin clone redirect-on-write example

When creating a thin clone of a file resource, the user can either clone a file system or a NAS server. When cloning a file system, the resulting clone is automatically added to the same NAS server as the source file system. After the clone is created, an SMB share or NFS export must be created to access the clone. When cloning a NAS server, the user can choose which file systems to include from the source NAS server. After creation, the user needs to configure one or more file interfaces on the cloned NAS server to access the data. If the NAS server will be attached to an active directory domain, a new SMB Computer Name must be provided that differs from the original NAS server.

Thin clones also support local and remote data protection. For a thin clone to be protected, manual snapshots can be taken at any time, or a protection policy can be assigned to it. Figure 35 shows an example of a thin clone with a protection policy assigned. It contains a snapshot rule and an RPO-based replication rule. The resource is also mapped to a host for access.

Figure 35.    Thin clone data protection example

Thin clones within PowerStore are treated as an autonomous resource, as if they were a separate volume, volume group, NAS server, or file system. When created, they are listed on the main resource page, such as the Volumes or File Systems page. The properties window for a thin clone contains the same information as other resources, and the method to delete a thin clone is also the same. As an added benefit, parent resources can be deleted without deleting their thin clones. This action does not impact the thin clone or any snapshots the thin clone may have.

Use thin clones to create and manage space-efficient copies of production environments, which is beneficial for the following types of activities:

• Development and test environments: Thin clones allow test and development personnel to work with real workloads and use all data services that are associated with production storage resources without interfering with production. They also allow development personnel to promote a test thin clone to production.
• Parallel processing: Parallel processing applications that span multiple servers can use multiple thin clones of a single production data set to achieve results more quickly.
• Online backup: Use thin clones to maintain hot backup copies of production systems. If there is corruption in the production data set, the read/write workload can be immediately resumed using the thin clones.
• System deployment: Use thin clones to build and deploy templates for identical or near-identical environments. For example, create a test template that is thin cloned as needed for predictable testing.