Practical difference between writable snap and clone?

[bubbagump41]

With a typical snap taken on a schedule it is non-writable. You have three options with it

• Put it online and it behaves as a read-only volume.
• "Restore" it and it overwrites the original volume to the point in time of the snap.
• Clone it and it behaves as a new writable volume.

What is confusing is how are clone and a writable snap different? They sound identical to me in practice?

[chris24]

Hello,

Good question! A clone operates as a new branch, a new volume with all the data of the original snapshot without duplicating all the space, the difference with an online snapshot:

• You can create as many clones of them as you wish, this is huge in the smartstack / docker world where 100's of volumes can be provisioned.
• A cloned volume acts as a volume (a new branch), you can protect snapshot & replicate it.

As a rule of thumb I advise using clones always, much easier to keep track of them (and rename). A process that typical makes use of online snapshots is a backup verification process.

Many thanks,

Chris