Activate z11 mode

Description

JES2 z/OS V2R1 is the last release level that will support z2 checkpoint mode. JES2 must be activated to z11 mode before migrating to z/OS V2R2. Activating z11 mode upgrades the JES2 checkpoint and enables JES2 function that is introduced in z/OS V1R11, including JOE data area extensions supported by BERTs. For more information on the JES2 functionality introduced in z/OS V1R11, see Reference information.

Table 1 provides more details about this migration action. Use this information to plan your changes to the system.

Table 1. Information about this migration action
Element or feature: JES2.
When change was introduced: z/OS V2R2.
Applies to migration from: z/OS V2R1 and z/OS V1R13.
Timing: Before installing z/OS V2R2.
Is the migration action required? Yes
Target system hardware requirements: None.
Target system software requirements: None.
Other system (coexistence or fallback) requirements: None.
Restrictions: You are able to fall back to z2 mode, if necessary, prior to z/OS V2R2. After z/OS V2R2, you cannot fall back to z2 mode.
System impacts: None.
Related IBM® Health Checker for z/OS® check: Use check JES2_Z11_Upgrade_CK_JES2 to determine if your system is ready to upgrade the JES2 checkpoint to z11 mode. For more information, see IBM Health Checker for z/OS User's Guide.

Steps to take

Follow these steps:
  • After migrating to z/OS V1R11 JES2, or later, on all systems in your MAS, determine your z11 checkpoint activation readiness:
    1. Use the $D ACTIVATE command. This command indicates if activation to z11 mode will succeed.
    2. Review your current utilization of BERT data to determine if there are sufficient BERTS, as detailed in Check BERT utilization.
    3. If you issue the $ACTIVATE,LEVEL=z11 command, activation of LARGEDS support is required.
    4. An additional nnn 4K records for CKPT1 is required for z11 mode.
  • Run the JES2 $ACTIVATE command to verify non-configuration changes that must be accommodated before going to z11, and to activate z11 mode following the considerations for this command found in z/OS JES2 Commands.
    Note: The SPOOLDEF LARGEDS=FAIL (default value) in JES2PARM parmlib member is not supported in z11 mode. In z11 mode, on a COLD start, JES2 defaults to LARGEDS=ALLOWED. However, you cannot issue the $ACTIVATE,LEVEL=z11 command in the environment of SPOOLDEF LARGEDS=FAIL.

By default, JES2 V1R13 and V2R1 restart in the same mode (z2 or z11) as other members of the MAS (if any are active) or the mode the last active JES2 member was in when it came down. To restart JES2 in z2 mode, specify UNACT on PARM=. On a cold start, JES2 starts in z11 mode unless overridden by OPTSDEF COLD_START_MODE or UNACT parameter.

Reference information

For more information, see the following references:
Parent topic: JES2 actions to perform before installing z/OS V2R2