ATTEST: ATTributes-based Extendable STorage

The total amount of stored information on disks has increased tremendously in recent years. With storage devices getting cheaper and government agencies requiring strict data retention policies, it is clear that this trend will continue for several years to come. This progression creates a challenge for system administrators who must determine several aspects of storage policy with respect to provisioning, backups, retention, redundancy, security, performance, etc. These decisions are made for an entire file system, logical volume, or storage pool. However, this granularity is too large and can sacrifice storage efficiency and performance – particularly since different files have different requirements. In this paper, we advocate that storage policy decisions be made on a finer granularity. We describe ATTEST, an extendable stackable storage architecture, that allows storage policy decisions to be made at a file granularity and at all levels of the storage stack through the use of attributes that enable plugin policy modules and application aware storage functionality. We present an implementation of ATTEST that shows minimal impact on overall performance.