Techniques manage redundant arrays of independent drives (RAID). The techniques involve: in response to a target stripe to be built in the RAID, determining, from a resource pool, whether there are spare extents associated with at least one system disk. The techniques further involve: in response to determining that there are spare extents associated with at least one system disk, determining an adjacent relationship of used extents associated with the at least one system disk within a RAID stripe. The techniques further involve: determining, based on the adjacent relationship and the spare extents, an extent for building the target stripe. Accordingly, the total number of the RAID stripes including extents associated with the system disks can be reduced significantly, and a balance can be achieved within spare extents associated with system disks and spare extents associated with user disks for building a RAID stripe.