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SYSIN datasets remain allocated to CICS while CICS is active

Technote (troubleshooting)


You are unable to deallocate the SYSIN dataset while CICS is active. You specify FREE=CLOSE on each SYSIN DD statement and expect the dataset to be deallocated from CICS once the file is closed. Normally the close occurs just after CICS has read the SYSIN parameters during initialization. However, the SYSIN datasets remain allocated to CICS until it is shutdown. This stops you from being able to delete and reallocate the dataset while CICS is running. You are able to successfully deallocate other datasets that specify FREE=CLOSE in the CICS JCL.


Your CICS SYSIN input consists of several concatenated PDS datasets. An MVS restriction is causing FREE=CLOSE to be ignored due to the dataset being a member of a concatenated group.

Resolving the problem

Use the ADYN transaction to dynamically deallocate a file from CICS while CICS is up. Prior to using ADYN you must install group DFH$UTIL in your CICS region. This group contains the transaction definition for ADYN and its associated program, DFH99.

Here is an example of the commands that can be used to deallocate the file "MYFILE.CICSTS13.SYSIN" and reallocate it:
1. Enter ADYN from a blank CICS screen
2. Enter free ddname(sysin) unalloc
3. Enter alloc ddname(sysin) dsname(MYFILE.CICSTS13.SYSIN) status(shr)

To end ADYN, first clear the CICS screen (clear the screen and erase EOF on the command line). Then hit enter on the empty screen.

ADYN is documented to in the CICS TS information center under the dynamic allocation sample program. You can also see the ADYN options that are available by entering ADYN from a blank CICS screen. You will see the following:

Then enter ?. You will see the available options as shown below:

Note: This Technote is for datasets that have DD statements in the CICS startup JCL. You can use CEMT to deallocate user files that do not have DD statements.

Product Alias/Synonym

CICS/TS CICS TS CICS Transaction Server

Document information

More support for: CICS Transaction Server
File Control

Software version: 3.1, 3.2, 4.1, 4.2, 5.1

Operating system(s): z/OS

Reference #: 1078727

Modified date: 19 March 2013

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