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This article is presented by:.
SHAMMI PRIYADARSHI
DIVISION OF INFORMATION TECHNOLOGY
SCHOOL OF ENGINEERING
COCHIN UNIVERSITY OF SCIENCE AND TECHNOLOGY
KOCHI-22
ZFS (Zettabyte FileSystem)
ABSTRACT
ZFS (Zettabyte FileSystem) is a file system designed by Sun Microsystems for the Solaris Operating System. ZFS is a 128-bit file system, so it can address 18 billion billion times more data than the 64-bit systems ZFS is implemented as open-source filesystem, licensed under the Common Development and Distribution License (CDDL). The features of ZFS include support for high storage capacities, integration of the concepts of file system and volume management, snapshots and copy-on-write clones, continuous integrity checking and automatic repair, RAID-Z etc. Additionally, Solaris ZFS implements intelligent prefetch, performing read ahead for sequential data streaming, and can adapt its read behavior on the fly for more complex access patterns. To eliminate bottlenecks and increase the speed of both reads and writes, ZFS stripes data across all available storage devices, balancing I/O and maximizing throughput. And, as disks are added to the storage pool, Solaris ZFS immediately begins to allocate blocks from those devices, increasing effective bandwidth as each device is added. This means system administrators no longer need to monitor storage devices to see if they are causing I/O bottlenecks.
INTRODUCTION
Anyone who has ever lost important files, run out of space on a partition, spent weekends adding new storage to servers, tried to grow or shrink a file system, or experienced data corruption knows that there is room for improvement in file systems and volume managers. Solaris ZFS is designed from the ground up to meet the emerging needs of a general purpose local file system that spans the desktop to the data center. Solaris ZFS offers a dramatic advance in data management with an innovative approach to data integrity, near zero administration, and a welcome integration of file system and volume management capabilities. The centerpiece of this new architecture is the concept of a virtual storage pool which decouples the file system from physical storage in the same way that virtual memory abstracts the address space from physical memory, allowing for much more efficient use of storage devices. In Solaris ZFS, space is shared dynamically between multiple file systems from a single storage pool, and is parceled out of the pool as file systems request it. Physical storage can be added to or removed from storage pools dynamically, without interrupting services, providing new levels of flexibility, availability, and performance. And in terms of scalability, Solaris ZFS is a 128-bit file system. Its theoretical limits are truly mind-boggling — 2128 bytes of storage, and 264 for everything else such as file systems, snapshots, directory entries, devices, and more. And ZFS implements an improvement on RAID-5, RAID-Z, which uses parity, striping, and atomic operations to ensure reconstruction of corrupted data. It is ideally suited for managing industry standard storage servers like the Sun Fire 4500.
