IBM Hub/Switch 6.6.1 Congure the Migration Policies

Chapter 6 HPSS Conﬁguration

280 September 2002 HPSS Installation Guide

Release 4.5, Revision 2

6.6.1 Conﬁgure the Migration Policies

A migration policy is associated with a storage class and deﬁnes the criteria by which data is

migratedfrom that storage class to storage classes at lower levels in the storage hierarchies. Note,

however,that it is the storage hierarchy deﬁnitions, not the migration policy,which determines the

numberand location of the migration targets. Also note that a storage class may be used in multiple

hierarchies and may have different migration targets in each.

A single basic migration policy must be assigned to any disk or tape storage class which requires

migration services. This basic migration policy determines the migration parameters for this

storage class across all storage subsystems. This is the simplest way to control migration on a

storage class. If it is desired for migration on a storage class to behave differently within different

subsystems, storage subsystem speciﬁc migration policies may be added which override the

defaultvalues in the basic policy for the given storage class in the selected subsystem. The storage

subsystemspeciﬁc migration policies share the same migration Policy ID and Policy Name with the

basic policy.

Both basic and subsystem speciﬁc migration policies are created using the Migration Policy

window. The basic policy must be created before it is possible to create the subsystem speciﬁc

policies. After the policies are created, they may be viewed, updated, or deleted using the same

window. From theHPSS Health and Status window (shown in Figure 6-1 on page 252), click on

theAdmin menu, select the Conﬁgure HPSS option, and click on theMigration Policies option.

TheMigration Policy window will be displayed as shown in Figure 6-7 on page 282. The ﬁelds in

thebasic policy are displayed with default values for a new policy. If the default data for the basic

policy is not desired, change the necessary ﬁelds with the desired values. Click on theAdd Basic

buttonto write the new basic policy to the metadata ﬁle. To conﬁgure a subsystem speciﬁc policy,

selectan existing basic policy as described below. Once the existing basic policy is displayed, click

onthe Start New button on the Storage Subsystem-Speciﬁc Policy portion of the Migration Policy

window.The ﬁelds in the new subsystem speciﬁc policy are displayed with data extracted from the

basic policy. Change the desired ﬁelds in the subsystem speciﬁc policy and then use theAdd

Speciﬁc button to write the new subsystem speciﬁc policy to the metadata ﬁle.

To update an existing basic migration policy, select theLoad Existing button on the Basic Policy

portion of theMigration Policy window and select the desired policy from the popup list. The

window will be refreshed with the conﬁgured basic policy data. After modifying the basic policy,

click on theUpdate Basic button (which is only visible when no subsystem speciﬁc policy is

selected) to write the changes to the metadata ﬁle. To update an existing subsystem speciﬁc

migration policy, ﬁrst select and load the existing basic policy as described above. Then use the

Load Existing button and popup list on theStorage Subsystem- Speciﬁc Policy portion of the

MigrationPolicy window to load the desired subsystem speciﬁc migration policy.After modifying

the subsystem speciﬁc policy, click on theUpdate Speciﬁc button (which is only visible when a

subsystem speciﬁc policy is selected) to write the changes to the metadata ﬁle.

To delete an existing migration policy, ﬁrst delete all of the subsystem speciﬁc policies, and then

deletethe basic policy. Use the Load Existing button and popup list on the Basic Policy portion of

thescreen to select the overall policy to be deleted. Next, use the Load Existing button and popup

list on theStorage Subsystem-Speciﬁc Policy portion of the screen to select the ﬁrst of the

subsystemspeciﬁc policies to be deleted. Use the Delete Speciﬁc button (which is only visible after

a subsystem speciﬁc policy has been selected) to delete each of the subsystem speciﬁc policies in

turn.Finally, use the Delete Basic button (which is only visible when no subsystem speciﬁc policy

is selected) to delete the basic migration policy.