How can I remotely determine if there's any RAID configuration in use?
With most operating systems if you can remote into a system and you have a sufficient privileges you can see whether software RAID is configured, or if hardware RAID is in use. For the software case there's nothing to stop you finding the precise configuration but for hardware RAID you will typically only be able to see that there are volumes provided by a RAID capable controller but not what RAID type (if any) are actually used.
If you have an out-of-band management solution (iDRAC\iLO\BMC..) you can usually get the precise hardware RAID config from that. Likewise if you have vendor hardware management tools installed in the operating system (Dell OpenManage etc) you can get that level of detail from that too.
Then there is SAN attached storage - again without SAN tools installed in the OS you will have no way of telling what the underlying RAID type for the SAN attached volumes is.
One case where this definitely wont be true is if the remote system is a Virtual Machine - without access to the Hypervisor or hardware directly you can't get any information about the underlying disk structure - RAID will almost certainly be used either locally or via a SAN but the VM will have no way to get that information.
Hardware raids are normally a little more complicated..
Generally I try some of these
finally there is usally a bunch of tools installed for the raid controller if its supported..