Managing virtual tape
Learn the necessary steps to manage your virtual tape.
- Perform a save operation
- To save to virtual tape storage, see Virtual tape media.
- Perform a restore operation
- To restore from virtual tape storage, see Recovering your system.
- Duplicating virtual tape to physical media
- When you duplicate virtual tape volumes to physical tape devices you need to make sure that the virtual tape volumes are created using a block size that is compatible with your physical tape device. The density (format) of the virtual tape volumes is used to control the maximum size for the blocks of data on the virtual tape volume. To determine the block size that your tape device supports, see Formatting of virtual tape images.
- Using volumes in dependent image catalogs
- A dependent catalog provides a read-only view of the virtual
tape volumes that are within a reference image catalog. For example,
if an image catalog existed named JOE, then the following command
would be entered on the command line to create a dependent image catalog
based on image catalog JOE:
All of the volumes in the reference image catalog (JOE) are accessible when the dependent image catalog (JOEDEP) is mounted in a separate virtual tape device. The dependent image catalogs are not synchronized with additional changes that are made to the reference image catalog. Multiple dependent image catalogs can be created all pointing to the same reference catalog. The same virtual tape volume can be mounted in several virtual devices at the same time through the use of dependent image catalogs. This mounting procedure enables the same virtual tape volume to be used for input operations by multiple users at the same time.CRTIMGCLG IMGCLG(JOEDEP) DIR(*REFIMGCLG) TYPE(*TAP) REFIMGCLG(JOE) - Using virtual tape from other partitions
- A Linux® guest partition can use the virtual tape devices and the currently mounted volume.
- Using virtual tape volumes in user ASPs
- Create a User Defined File System for the user ASP that can be
made visible to the rest of the integrated file system name space.
- CRTUDFS UDFS('/dev/qaspXX/aspXX.udfs'), where XX is the ASP number
- Add a new directory to the system that will be used as the mount
point directory for the User Defined File System created in step 1.
- MKDIR DIR('/your-path') to make a mount point directory
- Make the objects in the User Defined File System accessible to
the integrated file system name space. The mount point directory
is assigned as the first part of the path name, which is used to access
the objects.
- MOUNT TYPE(*UDFS) MFS('/dev/qaspXX/aspXX.udfs') MNTOVRDIR(your-path) Note: Anything that is created in '/your-path' is created in the UDFS.
- MOUNT TYPE(*UDFS) MFS('/dev/qaspXX/aspXX.udfs') MNTOVRDIR(your-path)
- Use the CRTIMGCLG command to create an image catalog with the
mount point in the first part of the path name.
- CRTIMGCLG IMGCLG(USERASP) DIR('/your-path/image-directory') TYPE(*TAP)
Note: You cannot specify only the mount-point directory when you specify a path-name with the CRTIMGCLG command. The path name must include a directory below the mount-point directory.- Create a User Defined File System for the user ASP that can be
made visible to the rest of the integrated file system name space.
- Using virtual tape volumes in independent disk pool
- To use a virtual tape volume in an independent disk pool, specify the disk pool device name as the first part of the integrated file system path name. The independent disk pool must be varied on before the virtual tape volumes are usable.
- Image files *ALWSAV attributes
- When the image catalog is in ready status, all of the image catalog's images have an *ALWSAV attribute value of *NO with the CHGATR command. This does not allow the images to be saved by the Save Object (SAV) command or the QsrSave API. When the image catalog is not in ready status, all of the image catalog's images have an *ALWSAV attribute value of *YES. This allows the images to be saved.