Consolidated storage service receives its momentumin the building of various IT system infrastructures be-cause of its cost efficiency, reliability, and maintain-ability. Meanwhile, only when users who run their ap-plications on the consolidated storage system have asimilar or better performance experience compared tothose using direct-attached storage on each server canthe storage design really be widely accepted. We pro-pose a framework in which performance of servicingrequests from one user is well isolated from that for theothers in such a way that each user can be regardedas being allocated an independent virtual disk (VD)of performance as specied in its service-level agree-ment (SLA). Three SLA expressions that we believeare most tangible to users are supported in the spatial-locality-aware framework, which we name as rent-a-disk, latency-conscious, and throughput-conscious.Our proposed I/O scheduling algorithm for implement-ing the three types of VDs provides strong isolation, lowinterference, and highdelity of performance for eachVD if SLA is not violated. Our algorithm also enablesdierent types of VDs to cooperate with each other toimprove performance for each VD as well as for theentire physical storage.