For purposes of recovery, treat an SCDS the same as any other source VSAM linear data set. You can use DFSMShsm to manage its availability, which relieves you from having to allocate any spares.
If the SCDS and its backups are lost, you can save the ACDS as an SCDS using the SETSMS SAVESCDS command. For more information about how to use this command, see Parameters of the SETSMS operator command.