/NRESTART command

Subsections:

• Environment
• Syntax
• Keywords
• Usage notes
• Examples

Environment

The following table lists the environments (DB/DC, DBCTL, and DCCTL) in which you can use the commands and keywords.

Syntax

Figure 0. Cold start with no previous shutdown

Notes:

• ¹ The FORMAT keyword must be followed by at least one of the SM, LM, QC, RS, WA, or ALL parameters.

Figure 0. Warm start after a /CHECKPOINT FREEZE command

A

B

Notes:

• ¹ The FORMAT keyword must be followed by at least one of the SM, LM, QC, RS, WA, or ALL parameters.

Figure 0. Warm start after a /CHECKPOINT PURGE or /CHECKPOINT DUMPQ command

A

B

Notes:

• ¹ The FORMAT keyword must be followed by at least one of the SM, LM, QC, RS, WA, or ALL parameters.

Keywords

The following keywords are valid for the /NRESTART command:

BUILDQ | NOBUILDQ

BUILDQ requests that the message queues dumped on the log be loaded into the message queue data sets. BUILDQ is optional for a warm start after a /CHECKPOINT PURGE or /CHECKPOINT DUMPQ.

The BUILDQ keyword must be included if the message queues are to be restored after being formatted. If the BUILDQ keyword is specified, the log from the last /CHECKPOINT DUMPQ or /CHECKPOINT PURGE is required, slowing down the restart process.

If /NRESTART FORMAT is specified without the BUILDQ keyword, the NOBUILDQ keyword must be specified. Specifying NOBUILDQ reformats the queues in question and all messages are lost.

If an /NRESTART BUILDQ command fails, and then the /ERESTART CHECKPOINT 0, /ERESTART COLDCOMM, or /ERESTART COLDSYS command is performed, the messages are lost. IBM® IMS Queue Control Facility for z/OS® can be used to recover the local message queues.

In a shared-queues environment, the BUILDQ keyword is ignored because the message queue data sets are not used.

CHECKPOINT

Identifies the shutdown/restart sequence. CHECKPOINT 0 must be specified for a cold start.

CMDAUTH

Specifies that both signon (user identification verification) and command authorization for static and ETO terminals are in effect at the end of the emergency restart. (Command authorization is same as specifying RCF=S on the startup parameter.)

To specify CMDAUTH, you must specify RCF=A|Y|T|C|S as an initialization EXEC parameter.

CMDAUTHE

Specifies that command authorization for ETO terminals (same as RCF=S on the startup parameter) is in effect at the end of the emergency restart. CMDAUTHE also resets command authorization for static terminals, if it was set.

To specify CMDAUTHE, you must specify RCF=A|Y|T|C|S as an initialization EXEC parameter.

FORMAT

Specifies which queues or data sets should be formatted as part of the restart process when:

• A message queue or data set I/O error occurs.
• The size of a message queue or data set is to be changed.
• A message queue or data set is to be reallocated.

Specify one or more of the following or ALL:

SM

Short-message queue

LM

Long-message queue

QC

Control record data set

RS

Restart data set

WA

Write-ahead data set

ALL

All message queues (SM and LM) and data sets (QC, WA, and RS)

When FORMAT ALL is specified, do not also specify SM, LM, QC, WA, or RS. FORMAT ALL is only required at IMS initialization (first time use of the system).

You can specify any combination of SM, LM, QC, WA, and RS; for example, FORMAT LM RS.

In a shared-queues environment, the LM, SM, and QC parameters are ignored because the message queue data sets are not used. If you specify ALL, IMS does not attempt to format the message queue data sets.

The following table shows the environments in which the parameters are valid.

Table 2. /NRESTART FORMAT command parameter environments

Parameter	DB/DC	DBCTL	DCCTL
SM	X		X
LM	X		X
QC	X		X
RS	X	X	X
WA	X	X	X
ALL	X	X 1	X
Note: Supports only RS and WA parameters.

MSDBLOAD

Requests that the MSDBs be loaded from the z/OS sequential data set MSDBINIT instead of the MSDB checkpoint data set. Use the MSDBLOAD keyword only when an MSDB initial load is required; otherwise, omit it from the /NRESTART command. After you modify an MSDB DBD, you must specify MSDBLOAD on the next warm start of IMS in order for the changes to be effective.

MSDBLOAD is not required:

• For warm starts when the MSDB checkpoint data set is used.
• For a cold start because the MSDBs are loaded from the z/OS sequential data set MSDBINIT and the MSDB checkpoint data sets are formatted.

MULTSIGN

Permits multiple signons for each user ID.

In an IMSplex with Resource Manager and a resource structure, if MULTSIGN conflicts with the single user signon definition for the IMSplex, a warning message will be issued.

NOCMDAUTH

Resets command authorization on static and ETO terminals.

NOCMDAUTHE

Resets command authorization for static and ETO terminals. The command authorization is reset for static terminals because the command authorization for static terminals cannot exist without the command authorization for ETO terminals.

NOTRANAUTH

Turns off transaction authorization. NOTRANAUTH is not the opposite of TRANAUTH. TRANAUTH sets transaction authorization and also turns on signon (user identification verification).

If you specify NOTRANAUTH, it is rejected with an error message if TRN=F was specified as a JCL EXEC parameter.

NOUSER

Specifies that none of the following is in effect at the end of the emergency restart:

• transaction authorization
• user identification verification
• command authorization

You can use /NRESTART NOUSER for a warm start, but if transaction or command authorization is set from the checkpoint data, NOUSER is ignored, and signon (user identification verification) is set on.

SNGLSIGN

Permits a single signon for each user ID.

In an IMSplex with Resource Manager and a resource structure, if SNGLSIGN conflicts with the single user signon definition for the IMSplex, a warning message will be issued.

TRANAUTH

Specifies both transaction authorization and user identification verification, with or without RACF®.

To specify TRANAUTH, you must specify RCF=A|Y|T|C|S as an initialization EXEC parameter.

USER

Specifies user identification verification. User identification verification means that signon is required by static terminals. This keyword has no effect on ETO terminals, because they are always required to sign on. User identification verification can be forced on by the TRANAUTH or CMDAUTH keyword

To specify USER, you must specify RCF=A|Y|T|C|S as an initialization EXEC parameter.

Usage notes

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

When IMS initializes, the system parameters used for this initialization can come from the IMS system generation, from a PROCLIB member, or from EXEC statements that can override both the defaults and the PROCLIB members. Therefore, message DFS1929I is displayed showing the system parameters used for this particular initialization. The system parameters are also written to the job log.

For an IMS cold start, the base security definition is created from the IMS system definition and EXEC parameter specifications. For an /NRESTART warm restart, the base security definition is created from the IMS checkpoint data.

To override the base security definitions on a cold start, the security keywords of the /NRESTART command must be used.

The SGN=, TRN=, and RCF= startup parameters can be overridden by the /NRESTART command using the security keywords shown in the following table. A brief description of the keywords is also included.

If IMS is enabled to use the IMSRSC repository, IMS calls Resource Manager (RM) during warm start to read the change list, if one exists, for the IMS. The IMS change list is maintained by RM and is built if the IMPORT command with the SCOPE(ALL) keyword is issued while the IMS is down.

If a change list exists for the IMS that is being restarted, the database, program, transaction, and routing code resources and descriptors in the IMS change list and that apply to the IMS environment are quiesced and are not available for use until the stored resource definitions are imported from the repository.

After the IMS log is processed, IMS imports the stored resource definitions from the repository for the database, program, transaction, and routing code resources and descriptors in the IMS change list. It then applies the changes to the runtime resource and descriptor definitions in the IMS.

For the resources or descriptors that are in the IMS change list and that do not exist in IMS, the runtime resource definitions are created from the stored resource definitions in the repository. For the resource or descriptors that exist in IMS, the runtime resource definitions are updated with the stored resource definitions from the repository. The change list for the IMS system is deleted at the end of the warm start.

During cold start, if IMS is enabled to use the repository, the stored resource definitions are read from the repository. The change list is not processed during cold start because all the resource definitions are imported as part of cold start processing. Any change list in RM for the IMS being restarted is deleted.