/VUNLOAD command

The /VUNLOAD AREA command removes the specified areas from the z/OS® data space or coupling facility.

All of the updated CIs for the area are written to DASD. All subsequent I/O for the area is from DASD. /VUNLOAD processing occurs concurrently with application processing.

Subsections:

Environment

The following table lists the environments (DB/DC, DBCTL, and DCCTL) from which the command and keyword can be issued.

Table 1. Valid environments for the /VUNLOAD command and keyword
Command / Keyword DB/DC DBCTL DCCTL
/VUNLOAD X X  
AREA X X  

Syntax

Read syntax diagramSkip visual syntax diagram/VUNLOAD/VUNAREA areanameALL

Usage notes

In a data-sharing environment, in order to maintain data integrity, IMS requests IRLM to lock the first control interval (CI) in exclusive mode before IMS unloads the area from the coupling facility. This lock causes those IMS subsystems sharing the area to complete any synchronization point processing. When all sharing subsystems are no longer using the area, IMS requests IRLM to release the CI locks and IMS unloads the area. All subsequent I/O for the area is from DASD.

The /VUNLOAD command does not change any of the VSO options set in the RECON data set. Therefore, at the next IMS restart or /START AREA command, the VSO options again take effect. Any changes to VSO definitions must be made through DBRC commands. For Shared VSO areas however, the /VUNLOAD command is persistent across IMS restarts and can be reset only by a /START AREA command. This is true for shared VSO areas for consistency across all sharing partners. This prevents one system from accessing data from DASD while others are accessing from the coupling facility.

For multiple VSO DEDB areas that share a single coupling facility structure, when the /VUNLOAD AREA command is issued, one of the following actions may occur:
  • If there is only one area in the structure (either a single-area structure or a multi-area structure with one area), the area is taken out of VSO and the structure is deleted. The IMS issuing the /VUNLOAD AREA command notifies the other IMS systems sharing the area to disconnect from the structure.
  • If there are multiple areas in the structure, when one area is taken out of VSO, the area is disassociated and its CIs are deleted in the structure. The IMS issuing the /VUNLOAD AREA notifies the other IMS systems sharing the area to either disassociate or disconnect from the structure depending on if the IMS is still sharing or not sharing other areas in the structure.

If the /VUNLOAD command is issued for a local VSO DEDB area during application processing, an FH status code might be returned to the application programs.

This command can be issued to an IMSplex using the Batch SPOC utility.

Example

Entry ET: 
/VUNLOAD
Response ET: 
NC0000000 FPEC 03070 09:58:03.52 01   00000290  R 14,/VUN AREA DD01AR0
NR8400000 FPEC 03070 09:58:03.52 JOB00116 00000090  IEE600I REPLY TO 14 IS;/VUN AREA DD01AR0
N 8400000 FPEC 03070 09:58:03.53 JOB00116 00000090  DFS058I 09:58:03 VUNLOAD COMMAND IN PROGRESS   SYS3
W 8400000 FPEC 03070 09:58:03.53 JOB00116 00000090 *17 DFS996I *IMS READY*  SYS3
N 8400000 FPEC 03070 09:58:04.42 JOB00116 00000090  DFS2823I AREA DD01AR0  
	DISCONNECT FROM STR: DD01AR0STR1 SUCCESSFULS                                                    SYS3
N 8400000 FPEC 03070 09:58:04.42 JOB00116 00000090  DFS0488I VUN COMMAND COMPLETED. AREA= DD01AR0  RC= 0 SYS3