[zeec123]

> My preferred solution is to let client only write new backups, never delete.

I wish for syncoid to add this feature. I want it to only copy snapshots to the backup server. The server then deletes old snapshots. At the moment it requires delete permissions.

[KAMSPioneer]

You can do this by using a dedicated syncoid user and ZFS delegated permissions: https://openzfs.github.io/openzfs-docs/man/master/8/zfs-allo...

You'll need to add the --no-elevate-permissions flag to your syncoid job.