Dell R510 Raid Controller

It depends, Is it for storing the actual VMs? or Storage for the VM’s use?

If it is the first case, just make sure XCP-NG can use the RAID card.

If it’s the second case:
If you are using ZFS, it actually hurts to use a “hardware RAID”, as ZFS needs direct access to all the drives to warranty data integrity.

Afterall, “hardware RAID” is actually software RAID, running on a piece of hardware you don’t have complete control over it.