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

■ Adding or removing volumes does not require a file placement policy change.
If a volume with a tag value of vxfs.placement_class.tier2 is added to a file
system’s volume set, all policies that refer to tier2 immediately apply to the
newly added volume with no administrative action. Similarly, volumes can be
evacuated, that is, have data removed from them, and be removed from a file
system without a policy change. The active policy continues to apply to the
file system’s remaining volumes.
■ File placement policies are not specific to individual file systems. A file
placement policy can be assigned to any file system whose volume set includes
volumes tagged with the tag values (placement classes) named in the policy.
This property makes it possible for data centers with large numbers of servers
to define standard placement policies and apply them uniformly to all servers
with a single administrative action.
Tagging volumes as placement classes
The following example tags the vsavola volume as placement class tier1, vsavolb
as placement class tier2, vsavolc as placement class tier3, and vsavold as
placement class tier4 using the vxassist settagvxassist settag command.
To tag volumes
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Tag the volumes as placement classes:
# vxassist -g cfsdg settag vsavola vxfs.placement_class.tier1
# vxassist -g cfsdg settag vsavolb vxfs.placement_class.tier2
# vxassist -g cfsdg settag vsavolc vxfs.placement_class.tier3
# vxassist -g cfsdg settag vsavold vxfs.placement_class.tier4
# vxvoladm -g cfsdg settag vsavola vxfs.placement_class.tier1
# vxvoladm -g cfsdg settag vsavolb vxfs.placement_class.tier2
# vxvoladm -g cfsdg settag vsavolc vxfs.placement_class.tier3
# vxvoladm -g cfsdg settag vsavold vxfs.placement_class.tier4
Listing placement classes
Placement classes are listed using the vxassist listtagvxvoladm listtag
command.
See the vxassistvxvoladm(1M) manual page.
The following example lists all volume tags, including placment classes, set on a
volume vsavola in the diskgroup cfsdg.
Administering SmartTier
Placement classes
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