Modifying Topology Services and Group Services parameters

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You can use the chrsrc command to change the control parameters used by Topology Services or Group Services for an online cluster through IBM®.RSCTParameters resource class.

For a complete discussion of Topology Services, see The Topology Services subsystem. For a complete discussion of Group Services, see The Group Services subsystem. To obtain more information on the IBM.RSCTParameters resource class, use the lsrsrcdef command (as described in Displaying attribute definition information for a resource or a resource class).
An IBM.RSCTParameters resource class instance is created for each cluster when the cluster is first brought online. The control parameters include:
  • Topology Services log size (TSLogSize)
  • fixed priority (TSFixedPriority)
  • pinned regions (TSPinnedRegions)
  • Group Services log size (GSLogSize)
  • maximum directory size (GSMaxDirSize)
An instance of the class is created automatically for a cluster when the cluster is brought online the first time. The default values for these parameters will be used when it is created.
To view or change the RSCT parameters, you use generic RMC commands (lsrsrc and chrsrc as described below). To use these generic RMC commands, you need to first set the management scope to 2. 
export CT_MANAGEMENT_SCOPE=2
This tells RMC that the management scope is a peer domain.
To view the parameter values, issue the command: 
lsrsrc -c IBM.RSCTParameters
These values are tunable. They can be changed using one of the following commands: 
chrsrc -c IBM.RSCTParameters Attr=Value...
For example, to tell Topology Services to ping both code and data regions (a value of 3), execute the following command: 
chrsrc -c IBM.RSCTParameters TSPinnedRegions=3
The command is equivalent to the Topology Services tunable command (cthatstune) or the Group Services tunable command (cthagstune).