Silverstack helps you to back up camera cards to multiple destinations in one instance. While you can add various copy destinations for copying data in parallel, there’s a particular setting for a multi-destination backup called “Cascading Copy”.
In this blog post, we want to explore Silverstack’s Cascading Copy functionality, outline its similarities and differences compared to a regular multi-destination backup, and explain how exactly it benefits you.
What is Cascading Copy?
Cascading Copy is a special mode for backing up footage to two destinations. As indicated by its name, Cascading Copies follow a specific sequential process: After you schedule a backup to a first destination, the finished backup is used to automatically create a second backup in your second destination, instead of copying the source again.
Similarities and Differences To a Multi-Destination Backup
As the Cascading Copy setting also involves multiple destinations, you can describe it as a particular form of a multi-destination backup. In both cases, you’re able to create two checksum-controlled backups in two destinations.
However, the Cascading Copy setting follows a different set of rules and, most importantly, uses the first copy destination as the source for the second backup. In a typical multi-destination backup scenario, the slowest destination drive limits the speed of the copy process. In other words, you have to wait until your last backup is finished before you can return the camera card. The Cascading Copy setting creates a possibility to work around this common issue by automating a chain of backups.
Why Use Cascading Copy?
The main benefit is speed, as the Cascading Copy setting helps you free camera cards faster. It especially displays its effect when you involve a pretty fast and rather slow drive: You can back up to the fast destination first and return the camera card quickly. While the second backup runs, that card can already be used again. With the Cascading Copy setting, you don’t have to sacrifice speed for security – you free up the cards fast and still end up with two secure backups.
How to Set Up Silverstack for Cascading Copy
Now that we’ve outlined what the Cascading Copy feature can do for you, it’s time to show you how to set it up:
To run an offload to multiple destinations, you must add the destination drives in the Offload Wizard. As soon as enabling the checkbox for the Cascading Copy, you will see a label “1st Run” appear on the side of the copy destination, which lets you control the copy order.
Further details can be found in our dedicated Knowledge Base article on Cascading Copy.
Further Down the Cascade…
To conclude, let’s quickly tap on some more advanced topics because there’s more to explore:
For example, you can even set the verification behavior and the checksum method independently for 1st run and 2nd run jobs. This enables you to use a xxHash checksum for the 1st run while still running MD5 checksums to the slower destination where the speed limitations of MD5 might not play a role.
Moreover, you can define the number of parallel 2nd run jobs in the application preferences. This enables you to prioritize copy jobs from new incoming cards to run in parallel.
Lastly, you might have already wondered what happens when three copy destinations are involved. Well, you can also decide whether the third destination should belong to the 1st or 2nd run, so it will either be added as a destination to the 1st run offload or the 2nd run backup.
Given all discussed aspects, the Cascading Copy functionality can really be described as an integral part of Silverstack’s great toolset for optimizing your backup tasks.