ZFS Incremental Snapshot Backup & restore

[Magnetz]

I'm using ZFS snapshots and send/receive to push incremental snapshots to a USB drive. What is the situation regarding pruning of intermediary snapshots?

E.g. I have backup0, then incremental sends of backup1, backup2, backup3. All of which are sent to a pool on a USB drive

If I decide to prune and destroy backup2 from the main drive and the USB drive, and I somehow lose my main drive, can I still restore everything (obv. except backup2) from the USB drive? And all later snapshots? (send -R)

I was reading this and curious about the section

Without ONE incremental, following incrementals are useless

http://jrs-s.net/2016/09/15/zfs-snapshots-and-cold-storage/

 

[depasseg]

and send/receive to push incremental snapshots to a USB drive

Are you doing this manually, or using Replication in the GUI?

What is the situation regarding pruning of intermediary snapshots?

FreeNAS Replication will replicate all snapshots for the chosen dataset. If you delete a snapshot, those changes get rolled into other snapshots and those snapshots would be updated during the next replication.
If you are doing this manually, you need to do more reading, as there is a lot going on in the background.