Veritas™ File System Programmer's Reference Guide - Solaris

To define and assign an allocation policy to reallocate an existing file's data blocks to a specific volume

• To reallocate an existing file's data blocks to a specific volume (vol-03), create code similar to the following:

  /* Create a data policy for moving file's data */
  strcpy((char *) ap.ap_name, "Data_Mover_Policy");
  ap.ap_flags = FSAP_CREATE;
  ap.ap_order = FSAP_ORDER_ASGIVEN; 
  ap.ap_ndevs = 1;
  strcpy(ap.ap_devs[0], "vol-03");
  fd = open("/mnt", O_RDONLY);
  vxfs_ap_define(fd, &ap, 0);
  file_fd = open ("/mnt/file_to_move", O_RDONLY);
  vxfs_ap_assign_file(file_fd, "Data_Mover_Policy", NULL, 0);
  vxfs_ap_enforce_file(file_fd, "Data_Mover_Policy", NULL);

In this example, the files are under dir1, the metadata is allocated to vol-01, and file data is allocated to vol-02.

• To create policies to allocate new files under directory dir1, create code similar to the following:

  /* Define 2 policies */
  /* Create the RAID5 policy */ 
  strcpy((char *) ap.ap_name, "RAID5_Policy");
  ap.ap_flags = FSAP_CREATE | FSAP_INHERIT;
  ap.ap_order = FSAP_ORDER_ASGIVEN; 
  ap.ap_ndevs = 1;
  strcpy(ap.ap_devs[0], "vol-02");
  fd = open("/mnt", O_RDONLY);
  dir_fd = open("/mnt/dir1", O_RDONLY);
  vxfs_ap_define(fd, &ap, 0);
  /* Create the mirror policy */
  strcpy((char *) ap.ap_name, "Mirror_Policy");
  ap.ap_flags = FSAP_CREATE | FSAP_INHERIT;
  ap.ap_order = FSAP_ORDER_ASGIVEN; 
  ap.ap_ndevs = 1;
  strcpy(ap.ap_devs[0], "vol-01");
  vxfs_ap_define(fd, &ap, 0);
  /* Assign policies to the directory */
  vxfs_ap_assign_file(dir_fd, "RAID5_Policy", "Mirror_Policy",
                     0);
  /* Create file under directory dir1 */
  /* Meta and data blocks for file1 will be allocated on
      vol-01 and vol-02 respectively. */
  file_fd = open("/mnt/dir1/file1");
  write(file_fd, buf, 1024);