Sun Microsystems Fire X4540, Administration Manual

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78 Sun Fire X4500/ X4540 Servers Administration Guide • October 2008
Overview
ZFS is a 128-bit file system that provides 16 billion times the capacity of 32-bit or
even 64-bit file systems. With ZFS, data is protected by 64-bit checksums to provide
error detection and correction functionally. It constantly reads and checks data to
ensure that it is correct. If it detects an error in a mirrored pool, the technology
automatically repairs the corrupted data. ZFS is available in the Solaris 10 4/08 OS.
The ZFS ( Zettabyte File System) system delivers file system management
capabilities by automating common administrative tasks, protecting data from
corruption and providing virtually unlimited scalability.
Devices
Because ZFS file systems are not constrained to specific devices, they can be created
easily and quickly, similar to the way directories are created. ZFS file systems grow
automatically within the space allocated to the storage pool.
Historically, file systems have been constrained to one device so that the file systems
themselves have been constrained to the size of the device. Creating and re-creating
traditional file systems because of size constraints are time-consuming and
sometimes difficult. Traditional volume management products helped manage this
process.
Structure
ZFS uses virtual storage pools to make it easy to expand or contract file systems
simply by adding more drives. Instead of creating one file system, such as
/export/home, to manage many user subdirectories, you can create one file system
per user. In addition, ZFS provides a file system hierarchy so that you can easily set
up and manage many file systems by applying properties that can be inherited by
file systems contained within the hierarchy.
ZFS is a lightweight POSIX file system that is built on top of a storage pool. File
systems can be dynamically created and destroyed without requiring you to allocate
or format any underlying space. Because file systems are so lightweight and because
they are the central point of administration in ZFS, you are likely to create many of
them.