Using volume application programming interfaces


Using volume application programming interfaces
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The following pseudocode provides an example of using the volume APIs.

To shrink or grow a volume within a file system

Use the vxresize command to grow the physical volume.

To use the vxfs_vol_resize() call to shrink or grow the file system, create codes similar to the following:

/* stat volume "vol-03" to get the size information */
fd = open("/mnt");
vxfs_vol_stat(fd, "vol-03", infop);
/* resize (shrink/grow) accordingly. This example shrinks
       the volume by half */
vxfs_vol_resize(fd, "vol-03", infop->dev_size / 2);

To encapsulate a raw volume as a file

Add the volume to the volume set.

To encapsulate a raw volume vol-03 as a file named encapsulate_name in the file system /mnt, create code similar to the following:

/* Take the raw volume vol-03 and encapsulate it. The
    volume's contents will be accessible through the given
    path name. */
vxfs_vol_encapsulate("/mnt/encapsulate_name", "vol-03",
                                             infop->dev_size);
/* Access to the volume is through writes and reads of file
     "/mnt/encapsulate_name" */
encap_fd = open("/mnt/encapsulate_name");
write(encap_fd, buf, 1024);

To de-encapsulate a raw volume

To de-encapsulate the raw volume vol-03 named encapsulate_name in the file system /mnt, create code similar to the following:

/* Use de-ecapsulate to remove raw volume. After
   de-encapsulation, vol-03 is still part of volset, but is
   not an active part of the file system. */
vxfs_vol_deencapsulate("/mnt/encapsulate_name");

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