/* define is_migrated uses GPFS inode attributes that mark a file  as a migrated file. Use the define to include or exclude migrated  files from the policy scan result explicitly */ define( is_migrated, MISC_ATTRIBUTES LIKE '%V%') RULE 'SYSTEM_POOL_PLACEMENT_RULE' SET POOL 'system' RULE EXTERNAL POOL 'Archive_files' EXEC '/opt/ibm/ltfsee/bin/ltfsee' OPTS -p 'pool1' SIZE(20971520) RULE 'ARCHIVE_FILES' MIGRATE FROM POOL 'system' THRESHOLD(80,50) TO POOL 'Archive_files' WHERE PATH_NAME LIKE '/ibm/glues/archive/%' AND NOT (exclude_list) AND (NOT (user_exclude_list) OR (user_include_list)) AND (is_migrated OR is_premigrated) To ensure that a specified IBM Spectrum Scale is migrated only once, run the  mmapplypolicy command with the  - -single-instance  option. If this is not done, IBM Spectrum Archive EE  attempts to start another migration process every two minutes. It is called every two minutes  because the threshold continues to be exceeded while migrations are still in the process of  migrating the data to free up the space. As a preferred practice, the user should not use overlapping IBM Spectrum Scale policy rules  within different IBM Spectrum Scale policy files that select the same files for migration to  different tape cartridge pools. If a file is already migrated, later migration attempts fail, which  is the standard HSM behavior. However, this is not normally done, due to incorporating  thresholds. Important:  If a single IBM Spectrum Scale file system is used and the metadata directory  is stored in the same file system that is space-managed with IBM Spectrum Archive EE,  migration of the metadata directory must be prevented. The name of metadata directory is  /ibm/gpfs/.ltfsee/meta/ .  By combining the attributes of  THRESHOLD  and  WEIGHT  in IBM Spectrum Scale policies, you can  have a great deal of control over the migration process. When an IBM Spectrum Scale policy  is applied, each candidate file is assigned a weight (based on the  WEIGHT  attribute). All  candidate files are sorted by weight and the highest weight files are chosen to  MIGRATE  until  the low occupancy percentage (based on the  THRESHOLD  attribute) is achieved, or there are no  more candidate files. Example 7-60 on page 165 shows a policy that starts migration of all files when the file  system pool named “system” reaches 80% full (see the  THRESHOLD  attribute), and continues  migration until the pool is reduced to 60% full or less by using a weight that is based on the  date and time that the file was last accessed (refer to the  ACCESS_TIME  attribute). The file  system usage is checked every two minutes.  164  IBM Spectrum Archive Enterprise Edition V1.2.6: Installation and Configuration Guide