When you create a snapshot, Cassandra first flushes the application's memory. Then, it creates a hard-link to the
SSTable files. This means that the snapshots are application-consistent, but the data stored on the underlying volume can be corrupted. Thus, if a failure occurs on the underlying volume, the data will be corrupted.
A Portworx snapshot is a distinct volume from the one Cassandra is using, meaning that you can run a second instance of Cassandra in parallel using that volume. You can also use a Portworx snapshots to go back to a point in time where the issue is not present.Portworx by Pure Storage recommends you use 3DSnaps for Cassandra as they are application-consistent
Refer to the Configuring 3DSnaps page for more details about how you can create 3DSnaps.