DEFINE MDISK

Read syntax diagramSkip visual syntax diagram DEFine MDISK AS vdev start countEND volid

Authorization

Privilege Class: A

The user must be the primary system operator or the user's OPTION directory statement must include the DEVMAINT option.

Purpose

Use DEFINE MDISK to define a minidisk on the following media:
  • A system volume
  • The DASD volume that is attached to the system

Operands

vdev
AS vdev
identifies the virtual device number of the minidisk you are defining.
start
is a decimal number that defines the cylinder (CKD/ECKD) or block (FBA) on the real DASD that is cylinder 0 or block 0 for this minidisk.

Generally, ECKD user minidisks must begin with cylinder 1 or higher and FBA user minidisks must begin with block 32 or higher. If the SALIPL utility was used to install a copy of the Stand-Alone Program Loader (SAPL), then FBA user minidisks must begin with block 208 or higher.

count
END
defines the size of the minidisk.

The variable count is a decimal number that defines the number of cylinders or blocks to make up the minidisk.

END defines the minidisk to extend to the end of the real DASD.

volid
identifies the volume serial number (1- to 6-alphanumeric characters long) of the real DASD volume against which the MDISK is being defined.

Usage Notes

  1. The minidisk that you define remains available until you log off or detach the virtual device on which it resides. Use this command only for disaster recovery because it provides access to any area of a DASD volume without requiring more authorization.
  2. You can define a minidisk as a full-pack minidisk. You must define the starting cylinder number as zero and include all DASD volume primary cylinders and some or all of its alternate cylinders.
  3. Minidisks that are created by using the DEFINE MDISK command have cache access if they are on a cached control unit.
  4. Minidisks must not be defined on PAGE, SPOL, TDSK, or on DRCT allocation areas.
  5. FBA minidisks intended to be eligible for minidisk mapping and minidisk caching must start and end on a 4 K boundary. They must be defined with a number of blocks that comprise a complete number of pages (a multiple of 8 blocks) because partial pages are not formatted by ICKDSF CPVOLUME.
  6. A minidisk, including a temporary disk, is not eligible for minidisk cache if it has been defined with greater than 32767 cylinders. This does not apply to FBA devices. It applies only to ECKD devices.
  7. If you define a minidisk as virtual device number 192, the following special rules apply when you IPL CMS:
    • If 192 is unformatted, CMS formats it and accesses it as file mode D.
    • If 192 is CP-formatted, CMS reformats it for CMS use and accesses it as file mode D.
    • If 192 is CMS-formatted and accessed as a file mode other than D, CMS reaccesses it as file mode D.
    When CMS accesses a 192 minidisk as file mode D, any minidisk or SFS directory that is already accessed as D is released.
  8. When linking to a minidisk that has at least one cylinder that is the target of a persistent FlashCopy® relationship, warning message HCP116I is issued. The link is not prevented when a FlashCopy relationship exists.
  9. Minidisk cache is not supported for a minidisk that is defined on an Extended Address Volume (EAV) DASD, such as the 3390-0E, because of the large number of cylinders that are supported by that device.
  10. For additional information, see Usage Notes.

Responses

Response 1:
DASD vdev DEFINED
confirms the definition of the DASD.
vdev
identifies the virtual device number of the minidisk you define.

Response 2:

When minidisks that are in a FlashCopy relationship are defined, you see something like this:
DEFINE MDISK 200 100 100 PACK01
HCPLNS116I WARNING: Cylinders 50 through 59 of minidisk 0200 are the
HCPLNS116I          target of FlashCopy relationship 4AF7DB61.
Ready; T=0.01/0.01 14:48:25

DEFINE MDISK 300 100 100 PACK02
HCPLNS116I WARNING: Cylinders 50 through 59 of minidisk 0300 are the
HCPLNS116I          target of FlashCopy relationship 4AF7BDB3.
Ready; 0.01/0.01 14:48:29

Messages

  • HCP023E VOLID missing or invalid
  • HCP024E {CYLINDERS|PAGES} MISSING OR INVALID {Block number|Cylinder|Cylinder or block numbers} missing or invalid
  • HCP101E DASD vdev forced R/O; R/O by {nnnn users|userid|userid at sysname|userid ADJUNCT|userid ADJUNCT at sysname}[; stable by {nnnn users|userid|userid at sysname|userid ADJUNCT|userid ADJUNCT at sysname}]
  • HCP102E DASD vdev forced R/O; R/W by {nnnnn users|userid|userid at sysname|userid ADJUNCT|userid ADJUNCT at sysname}[; stable by {userid|userid at sysname|userid ADJUNCT|userid ADJUNCT at sysname}]
  • HCP103E DASD vdev forced R/O; R/W by {nnnnn users|userid|userid at sysname|userid ADJUNCT|userid ADJUNCT at sysname}, R/O by {nnnnn users|userid|userid at sysname|userid ADJUNCT|userid ADJUNCT at sysname}[; stable by {userid|userid at sysname|userid ADJUNCT|userid ADJUNCT at sysname}]
  • HCP104E userid vdev not linked; R/O by {nnnnn users|userid|userid at sysname|userid ADJUNCT|userid ADJUNCT at sysname }[; stable by {nnnn users|userid|userid at sysname|userid ADJUNCT|userid ADJUNCT at sysname}|exclusive by {userid|userid at sysname|userid ADJUNCT|userid ADJUNCT at sysname}]
  • HCP105E userid vdev not linked; R/W by {nnnnn users|userid|userid at sysname|userid ADJUNCT|userid ADJUNCT at sysname}[; stable by {userid|userid at sysname|userid ADJUNCT|userid ADJUNCT at sysname}|exclusive by {userid|userid at sysname|userid ADJUNCT|userid ADJUNCT at sysname}]
  • HCP106E userid vdev not linked; R/W by {nnnnn users|userid|userid at sysname|userid ADJUNCT|userid ADJUNCT at sysname}, R/O by {nnnnn users|userid|userid at sysname|userid ADJUNCT|userid ADJUNCT at sysname } [; stable by {userid|userid at sysname|userid ADJUNCT|userid ADJUNCT at sysname}]
  • HCP107E userid vdev not linked; not in CP directory
  • HCP108E userid vdev not linked; volid volid not mounted
  • HCP109E userid vdev not linked; invalid link device
  • HCP110E userid vdev not linked; type vdev already defined
  • HCP115E {LINK|AUTOLOG|XAUTOLOG} invalid; excessive incorrect passwords
  • HCP117E Userid userid not linked; volid volid conflict
  • HCP153E Device {vdev|range} exceeds maximum number of virtual devices
  • HCP1150E DASD {rdev|vdev} is not a valid base exposure.
  • HCP1151E userid vdev has not been linked because it is not within CP volume cylinder extents.
  • HCP1152E userid vdev has not been linked because it would overlap system {directory|spool|paging|temporary disk} space
  • HCP2880E userid vaddr is not linked, CSE LINK I/O error, code cc.

For the list of general messages for the DEFINE command, see Messages.