VSM_RUCSA_THRESHOLD

Description:

This check examines the current allocation of restricted use common service area (RUCSA) storage. This check is added only when a RUCSA is defined.

Reason for check:

When the current allocation has reached the user-specified or IBM-specified threshold value, an exception message and storage reports are created. The threshold report includes a comparison to high-water marks on the last IPL as well as the amount of the current allocation. The high-water mark is the highest amount of storage allocated since the system was IPLed.

If the threshold is specified as a percentage value (the default), an exception will be issued when the allocation of storage exceeds that threshold.
If the threshold is specified as a size in bytes, an exception will be issued when the remaining amount of storage is less than the specified size.

z/OS® releases the check applies to:

z/OS V2R4 and later.

Verbose support:

Yes. System-owned storage is evaluated for possible inclusion in the Five High Users Report when the check is run in verbose mode. You can put a check into verbose mode by using any of the following methods:

Specify the UPDATE filters, VERBOSE=YES parameter either on the MODIFY command or in a POLICY statement in an HZSPRMxx member of parmlib.
Overwrite the NO value with the YES value in the VERBOSE column of the SDSF CK command display.

Parameters accepted:

Yes, as follows:

When not using dyamic severity:
RUCSA(rucsabytes|rucsan%),ERUCSA(erucsabytes|erucsan%)
When using dynamic severity:
- RUCSA_HIGH(rucsabytes|rucsan%),RUCSA_MED(rucsabytes|rucsan%),
  RUCSA_LOW(rucsabytes|rucsan%),RUCSA_NONE(rucsabytes|rucsan%)
- ERUCSA_HIGH(erucsabytes|erucsan%),ERUCSA_MED(erucsabytes|erucsan%),
  ERUCSA_LOW(erucsabytes|erucsan%),ERUCSA_NONE(erucsabytes|erucsan%)

rucsabytes: A size, in bytes, with an optional suffix (K or M) indicating the minimum amount of unallocated RUCSA.
rucsan%: An integer (0 - 10000), followed by a percent sign (%), indicating the threshold percent for utilization of RUCSA below the line.
erucsabytes: A size, in bytes, with an optional suffix (K or M) indicating the minimum amount of unallocated ERUCSA.
erucsan%: An integer (0 - 10000), followed by a percent sign (%), indicating the threshold percent for utilization of ERUCSA above the line.

Default: RUCSA(80%),ERUCSA(80%)

You can use the following synonyms for the parameters:

Parameter	Synonyms
RUCSA_HIGH	RUCSA_HI RUCSA_H
RUCSA_MED	RUCSA_M
RUCSA_LOW	RUCSA_L
RUCSA_NONE	RUCSA_NO RUCSA_N
ERUCSA_HIGH	ERUCSA_HI ERUCSA_H
ERUCSA_MED	ERUCSA_M
ERUCSA_LOW	ERUCSA_L
ERUCSA_NONE	ERUCSA_NO ERUCSA_N

Note that when specifying percentages for parameter values, the values should increase as the severity increases, since the percentage specifies a percent-full amount (a larger value indicates a more severe condition), as shown in the following example:

PARM('RUCSA_HIGH(95%),RUCSA_MED(80%),RUCSA_LOW(60%),ERUCSA_HIGH(90%),ERUCSA_MED(70%)')

However, if you specify bytes for the parameter values, the values should decrease as the severity increases, since the values specify a bytes-remaining amount (a smaller value indicates a more severe condition), as shown in the following example:

PARM('RUCSA_HIGH(64K),RUCSA_MED(256K),ERUCSA_HIGH(128K),ERUCSA_LOW(1M)')

User override of IBM® values:

The following sample shows the defaults for customizable values for this check. Use this sample to make permanent check customizations in an HZSPRMxx member of parmlib used at IBM Health Checker for z/OS startup. If you want a one-time only update to the check defaults, omit the first line (ADDREPLACE POLICY) and use the UPDATE statement on a MODIFY hzsproc command. Note that using non-policy updates in an HZSPRMxx member can lead to unexpected results and is not recommended.

ADDREPLACE POLICY[(policyname)] [STATEMENT(name)]
UPDATE
CHECK(IBMVSM,VSM_RUCSA_THRESHOLD),
INTERVAL(00:05),
SEVERITY(HIGH),
PARM('RUCSA(80%),ERUCSA(80%)'),
DATE('date_of_the_change'),
REASON('Your reason for making the update.')

Reference:

For more information, see z/OS MVS Initialization and Tuning Reference.

Messages:

This check issues the following messages:

IGVH100E

See the IGVH messages in z/OS MVS System Messages, Vol 9 (IGF-IWM).

SECLABEL recommended for multilevel security users:

SYSLOW - see z/OS Planning for Multilevel Security and the Common Criteria for information on using SECLABELs.

Examples of message output for the VSM_RUCSA_THRESHOLD check

IGVH100E RUCSA has exceeded the threshold percentage of 80%          
Current allocation is 90% of 1M.                                     
Unallocated amount is 102K bytes.                                    
                                                                     
  Explanation:  The current allocation of RUCSA storage is 90% of 1M.
                                                                     
    This allocation exceeds the installation threshold.              
                                                                     
    102K bytes or 10% is still available.                            
                                                                     
    RUCSA/ERUCSA cannot be converted to SQA/ESQA.                    
                                                                     
    The highest allocation during this IPL is 90%.                   
...
IGVH100I The current allocation of ERUCSA storage is 128K of the total
size of 10M. (     1%) The IPL HWM for this allocation is 1%. Ensuring
an appropriate amount of storage is available is critical to the long 
term operation of the system. An exception will be issued when the    
allocated size of ERUCSA is greater than the installation specified   
threshold of 80%.