Recommend a software stack for a backup platform change that supports on-premise deployment, direct backups...

Veeam Backup and Recovery is the recommended software stack for a backup platform change that supports on-premise deployment, direct backups from Linux and Windows systems, NAS protocol support for the backup repository, and integration with HPE StoreOnce. Veeam is widely recognized for its robust and versatile backup capabilities, including full support for NAS, seamless integration with HPE StoreOnce for efficient deduplication and storage, and the ability to directly back up physical and virtual environments running on both Linux and Windows.

References:

Veeam Backup and Recovery Overview

HPE StoreOnce Integration