File Migration

Some SFS files controlled by DFSMS/VM may appear to reside in your file pool, but actually reside in a storage repository managed by DFSMS/VM. (Note that migrated files still are considered by SFS to consume their usual amount of room in your file space.) These files are said to be in migrated status in your file pool. (Files in DIRCONTROL directories are never migrated.) You can identify these files by issuing FILELIST (SHARE or LISTFILE. Migrated files are shown with an asterisk in the Type column.

These files act exactly like regular SFS files, but they must be recalled (either automatically or explicitly) into your actual file pool before you can access the data. This may cause a delay, depending on your system configuration and workload. Automatic recall is governed by the SET RECALL command, while explicit recall is performed with the DFSMS RECALL command. If SET RECALL is ON (the default), recall will happen automatically when the file data is referenced. (If you wish, you can add the SET RECALL setting to your PROFILE EXEC.) If SET RECALL is OFF, the file will not be recalled. You will get an error indicating that the file is migrated and will not be implicitly recalled. You can enter the DFSMS RECALL command to explicitly recall the file in this case. For more information about SET RECALL, see z/VM: CMS Commands and Utilities Reference, and for more information on the DFSMS RECALL, see z/VM: DFSMS/VM Storage Administration.

A file does not need to be recalled unless you need to access the file data itself (for example, with the XEDIT command.) You may query or change a file's attributes (LISTFILE, FILELIST FILEATTR, GRANT AUTHORITY, and so forth) without recalling the file. The file also does not need to be recalled to be erased, or to have its data replaced with COPYFILE (REPLACE.