INIT command—CKD

If you are installing 3380, 3390, or 9345 devices…

You should use the INSTALL command. See INSTALL command—CKD.
Versions: MVS VSE CMS SA

You use the INIT command to initialize volumes. There are three levels of initialization.

  1. Minimal initialization or minimal INIT refers to using the INIT command to write the volume label and VTOC on volumes for use by MVS or VSE operating systems. Minimal INIT is required for 3380, 3390, and 9345 devices after you use INSTALL or REVAL commands on MVS or VSE volumes. Minimal INIT is the only level of initialization valid for the 3995-151, 3995-153, and 3390-9 devices, and the minidisks.
  2. Medial initialization or medial INIT refers to using the INIT command to validate the home address and record 0, and then perform a minimal INIT on a volume.
    For 3375 and older devices, medial INIT is recommended for:
    • A new DASD unit
    • Replaced or upgraded HDA
    • A DASD unit that has been physically relocated

    For 3380, 3390, and 9345 devices, use the INSTALL command.

  3. Initialization for open-system DASD formats the volume for use as open-system DASD.

When initializing a volume, a flash copy withdraw is issued to release allocated space if the volume is a space efficient volume. The allocated space is released asynchronously and so may not be reported immediately. If the device being initialized is the source of a FlashCopy relationship, and the target of the relationship is a space efficient volume, the withdraw fails. In this case, ICKDSF fails the volume initialization and issues a message to the requestor that the relationship needs to be withdrawn prior to the initialization being processed.

Version: VM
Do not use the INIT command to perform a minimal INIT to volumes that are to be formatted for use in a VM environment. Use the CPVOLUME command instead.

When you initialize dual copy volumes, minimal initialization is the only level supported. Medial initialization requires that the volume is in simplex state.

For INIT support of minidisks and emulated devices, see:

For information on ICKDSF support of the RAMAC family of devices, see ICKDSF support of the RAMAC Array family.

For information on ICKDSF support of the Internal Disk devices, see ICKDSF support of the Internal Disk.