All files to be migrated must have more than 5 MB of disk space that is allocated for the file  (see the  KB_ALLOCATED  attribute). The migration is performed to an external pool, presented by  IBM Spectrum Archive EE ( /opt/ibm/ltfsee/bin/ltfsee ), and the data that is migrated is  sent to the IBM Spectrum Archive EE tape cartridge pool named  Tapepool1 . In addition, this  example policy excludes some system files and directories. In addition to monitoring the file system’s  overall usage in Example 7-60, you can monitor  how frequently a file is accessed with IBM Spectrum Scale policies. A file’s  access  temperature  is an attribute for a policy that provides a means of optimizing tiered storage. File  temperatures are a relative attribute, which indicates whether a file is “hotter” or “colder” than  the others in its pool.  The policy can be used to migrate hotter files to higher tiers and colder files to lower. The  access temperature is an exponential moving average of the accesses to the file. As files are  accessed, the temperature increases. Likewise, when the access stops, the file cools. File  temperature is intended to optimize nonvolatile storage, not memory usage. Therefore, cache  hits are not counted. In a similar manner, only user accesses are counted. The access counts to a file are tracked as an exponential moving average. A file that is not  accessed loses a percentage of its accesses each period. The loss percentage and period  are set through the configuration variables  fileHeatLossPercent  and  fileHeatPeriodMinutes . By default, the file access temperature is not tracked.  define ( exclude_list, ( PATH_NAME LIKE '%/.SpaceMan/%'  OR PATH_NAME LIKE '%/.ctdb/%' OR PATH_NAME LIKE '/ibm/glues/.ltfsee/%' OR NAME LIKE 'fileset.quota%' OR NAME LIKE 'group.quota%' ) ) RULE EXTERNAL POOL 'ltfsee' EXEC '/opt/ibm/ltfsee/bin/ltfsee'  OPTS -p‘Tapepool1' /* This is our pool in LTFS Enterprise Edition */ SIZE(20971520) /* The following statement is the migration rule */ RULE 'ee_sysmig' MIGRATE FROM POOL 'system'  THRESHOLD(80,60)  WEIGHT(CURRENT_TIMESTAMP - ACCESS_TIME)  TO POOL 'ltfsee'  WHERE (KB_ALLOCATED > 5120)  AND NOT (exclude_list) /* The following statement is the default placement rule that is required for a  system migration */ RULE 'default' set pool 'system' Example 7-60 Threshold-based migration in an IBM Spectrum Scale policy file Chapter 7. Operations  165