## 8.1 Preventing migration of the .SPACEMAN and metadata directories 

This section describes an IBM Spectrum Scale policy rule that you should have in place to help ensure the correct operation of your IBM Spectrum Archive EE system. 

You can prevent migration of the .SPACEMAN  directory and the IBM Spectrum Archive EE metadata directory of a GPFS file system by excluding these directories by having an IBM Spectrum Scale policy rule in place. Example 8-1 shows how an exclude  statement can look in an IBM Spectrum Scale migration policy file where the metadata directory starts with the text “ /ibm/glues/.ltfsee ”. 

define( user_exclude_list, ( PATH_NAME LIKE '/ibm/glues/.ltfsee/%' OR PATH_NAME LIKE '%/.SpaceMan/%' OR PATH_NAME LIKE '%/.snapshots/%' ) ) 

For more information and detailed examples, see 7.10.2, “Threshold-based migration” on page 161 and 7.10.3, “Manual migration” on page 166. 

## 8.2 Maximizing migration performance with redundant copies 

To minimize drive mounts/unmounts and to maximize performance with multiple copies, set the mount limit per tape cartridge pool to equal the number of tape drives in the node group divided by the number of copies. The mount limit attribute of a tape cartridge pool specifies the maximum allocated number of drives that are used for migration for the tape cartridge pool. A value of 0 means no limit and is also the default value. 

For example, if there are four drives and two copies initially, set the mount limit to 2 for the primary tape cartridge pool and 2 for the copy tape cartridge pool. These settings maximize the migration performance because both the primary and copy jobs are run in parallel by using two tape drives each for each tape cartridge pool. This action also avoids unnecessary mounts/unmounts of tape cartridges. 

To show the current mount limit setting for a tape cartridge pool, run the following command: 

ltfsee pool show -p <poolname> [-l <libraryname>] 

To set the mount limit setting for a tape cartridge pool, run the following command: 

ltfsee pool set -p <poolname> [-l <libraryname>] -a <attribute> -v <value> 

