Tuning the MVFS cache for a non-global zone using cleartool setcache

The cleartool setcache command has a –zone option that allows you to specify the MVFS cache size for a particular zone.

In addition to specifying mvfs_expected_zone_count, you can override the automatically computed values for a given zone by setting the scaling factor and cache sizes in that zone using the cleartool setcache -zone command from the global zone. Only the root user logged on to the global zone can run the setcache command.

To tune the MVFS performance for a non-global zone using the cleartool setcache command:

  1. Log on to the global zone as root.
  2. For each non-global zone, create a directory in the global zone that contains the configuration information for the non-global zone, and then use the Solaris zonecfg utility to map that directory to the non-global zone's file system hierarchy.
    1. In the global zone, create a directory to contain the configuration files for a non-global zone (where ngz-name represents the name of the non-global zone):

      mkdir –p /var/adm/rational/clearcase/mvfsconfig/zone/ngz-name

    2. Share the new directory via LOFS (loopback file system). Use the Solaris zone configuration application zonecfg.

      zonecfg -z ngz_name

    3. At the zonecfg prompt, type add fs to add and configure the file system. Enter the following commands at the zonecfg ngz_name:fs prompt:

      mkdir –p /var/adm/rational/clearcase/mvfsconfig/zone/ngz-nameset type=lofs
      add options [ro,nodevices]
      end

      Note: You must use the full path name (/var/adm/rational/clearcase/...). Symbolic links are not supported by zonecfg.
    4. Verify and commit the changes, and then exit the zone configuration application:

      verify
      commit
      exit

    5. Reboot the non-global zone ngz-name.
  3. Log on to the global zone as root.
  4. For each non-global zone for which you want to tune the MVFS cache, specify the MVFS tuning parameters using the cleartool setcache command:
    1. In the global zone, use cleartool setcache -z to set and save MVFS tuning settings in the MVFS configuration directory. For example, to set the MVFS scaling factor to 3 (for dynamic views):

      cleartool setcache –mvfs –zone ngz-name –persistent_only –scalefactor 3

    2. Reboot the non-global zone.
      Note: Currently, only persistent changes to MVFS tuning parameters are supported for non-global zones. This means that you must reboot the non-global zone before these changes take effect.

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