Zettabyte reliability with flexible end-to-end data integrity

We introduce flexible end-to-end data integrity for storage systems, which enables each component along the I/O path (e.g., memory, disk) to alter its protection scheme to meet the performance and reliability demands of the system. We apply this new concept to Zettabyte File System (ZFS) and build Zettabyte-Reliable ZFS (Z
²
FS). Z
²
FS provides dynamical tradeoffs between performance and protection and offers Zettabyte Reliability, which is one undetected corruption per Zettabyte of data read. We develop an analytical framework to evaluate reliability; the protection approaches in Z
²
FS are built upon the foundations of the framework. For comparison, we implement a straightforward End-to-End ZFS (E
²
ZFS) with the same protection scheme for all components. Through analysis and experiment, we show that Z
²
FS is able to achieve better overall performance than E
²
ZFS, while still offering Zettabyte Reliability.