Veritas Storage Foundation 5.1 SP1 Advanced Features Administrator"s Guide (5900-1503, April 2011)

About Thin Storage
Thin Storage is an array vendor solution for allocating storage to applications
only when the storage is truly needed, from a pool of free storage. Thin Storage
attempts to solve the problem of under utilization of available array capacity.
Thin Storage Reclamation-capable arrays and LUNs allow the administrators to
release once-used storage to the pool of free storage. Storage is allocated from
the free pool when files are created and written to in the file system. However,
this storage is not released to the free pool when files get deleted; the administrator
must perform the operation of reclaiming this storage for the free pool.
Veritas File System supports reclamation of the free blocks in the file system on
Veritas Volume Manager-backed file systems. The operation of reclamation can
be done on a disk group, LUN, enclosure, full file system, or part of a file system
using the vxdisk and fsadm commands, and the vxfs_ts_reclaim API.
About Thin Provisioning
Thin Provisioning is a storage array feature that optimizes storage use by
automating storage provisioning. Administrators do not have to estimate how
much storage an application requires. Instead, Thin Provisioning lets
administrators provision large thin or thin reclaim capable LUNs to a host. Physical
storage capacity is allocated from a thin pool to the thin/thin reclaim capable
LUNS only after application I/O writes.
About SF Thin Reclamation feature
You can use the Thin Reclamation feature in the following ways:
■ Space is reclaimed automatically when a volume is deleted. Because it is
asynchronous, you may not see the reclaimed space immediately.
■ You can trigger reclamation for a disk, disk group, or enclosure.
■ You can trigger reclamation for a VxFS file system.
About SmartMove
With Storage Foundation’s SmartMove feature, Veritas File System (VxFS) lets
Veritas Volume Manager (VxVM) know which blocks have data. VxVM, which is
the copy engine for migration, copies only the used blocks and avoids copying
unused blocks. This behavior helps optimize the thin storage utilization.
About SF Thin Storage optimization solutions
About Thin Storage
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