Snapshot VS Thin Clone

Question

Can someone please explain me the difference between doing an snapshot and a thin clone? As far as I am consult Snapshot Redirect on Write technology which means new writes to snapped storage resources or their snapshots are redirected to a new location in the same pool, and pointers are updated to point to the new location. A Thin Clone is a read-write copy of a Thin Block level storage resource (LUN, LUNs within Consistency Group, or VMware VMFS Datastores). A Thin Clone shares the underlying data blocks with the parent storage resource. Thin clone in Dell EMC Unity can only be done after we take an snapshot at that particular point of time from the Block or the File System . It would be a great help if someone could answer the key difference in taking an snapshot and a thin clone in DELL EMC UNITY

Rainer_EMC · Answer

From the Unity Snapshots and Thin clones white paper (which has more details):

Thin Clones use the same underlying pointer-based technology that snapshots use to provide a method for managing multiple copies of Block storage resources. Thin Clones support many data services, which engineers and developers can leverage in their testing development environments.

When users create a Thin Clone, despite some differences in the settings, it acts as a regular LUN and is listed on the LUNs page. Similar to snapshots, users can create, manage and destroy Thin Clones through Unisphere, CLI, and the RESTful API.

Joshi_Sushant · Answer

Hello Rainer, Thank you for your reply but I wanted to know the difference between Snapshot and Thin Clone ? Is there any advantage using Snapshot over Thin Clone and vice versa ?

Rainer_EMC · Answer

yes - see the white paper for details

https://www.dellemc.com/resources/en-us/asset/white-papers/products/storage/h15089-dell-emc-unity-snapshots-and-thin-clones.pdf

for example thin clones can be the source for a replication, created from consistency groups, ...

DELL_ChrisHolloway · Answer

Depends on your use case. Thin clones appear as a seperate LUN in Unisphere and can have their own data services applied to them, such as being the source of a new replication session, having it's own snapshot schedule and so on. Usually you would use thin clones for use cases like test/dev, UAT and so on where you need a copy of the production data that you want to treat with different data services. Snapshots could be used for the above, but usually they are more suited to data protection use cases.

Joshi_Sushant · Answer

Hello Rainer, I have read the documents but still the document clarify my points about being the main difference... Why would I have thin clone as I am already having an snapshot ?

Unity

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