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

for administrative purposes, making it possible to control the locations to which
individual files are directed.
See “About multi-volume support” on page 323.
Note: Some of the commands have changed or been removed between the 4.1
release and the 5.1 SP1 release to make placement policy management more
user-friendly. The following commands have been removed: fsrpadm, fsmove, and
fssweep. The output of the queryfile, queryfs, and list options of the fsapadm
command now print the allocation order by name instead of number.
In the previous VxFS 5.x releases, SmartTier was known as Dynamic Storage
Tiering.
SmartTier allows administrators of multi-volume VxFS file systems to manage
the placement of files and the placement of portions of files on individual volumes
in a volume set by defining placement policies. Placement policies control both
initial file location and the circumstances under which existing files are relocated.
These placement policies cause the files to which they apply to be created and
extended on specific subsets of a file system's volume set, known as placement
classes. The files are relocated to volumes in other placement classes when they
meet the specified naming, timing, access rate, and storage capacity-related
conditions.
You make a VxVM volume part of a placement class by associating a volume tag
with it. For file placement purposes, VxFS treats all of the volumes in a placement
class as equivalent, and balances space allocation across them. A volume may
have more than one tag associated with it. If a volume has multiple tags, the
volume belongs to multiple placement classes and is subject to allocation and
relocation policies that relate to any of the placement classes. Multiple tagging
should be used carefully.
See “Placement classes” on page 341.
VxFS imposes no capacity, performance, availability, or other constraints on
placement classes. Any volume may be added to any placement class, no matter
what type the volume has nor what types other volumes in the class have. However,
a good practice is to place volumes of similar I/O performance and availability in
the same placement class.
The Using SmartTier Symantec Yellow Book provides additional information
regarding the SmartTier feature, including the value of SmartTier and best
practices for using SmartTier. You can download Using SmartTier from the
following Web page:
http://www.symantec.com/enterprise/yellowbooks/index.jsp
Administering SmartTier
About SmartTier
340