ZFS_VERIFY_CACHESIZE
- Description:
- Checks whether the system is running with the default settings
for IOEFSPRM configuration options meta_cache, metaback_cache and
user_cache.
For user-defined user cache size, check if the current size is less than the default user cache size. For either or both user-defined metadata cache size and metadata backing cache size, check if the sum of the two metadata caches is less than the
default metadata cache size.
- Reason for check:
- Running with a very small cache size could affect zFS performance.
This check issues an exception message if either or both of the conditions
are true:
- For user-defined user cache size, check if the current size is
less than the default user cache size. For either or both user-defined
metadata cache size and metadata backing cache size, check if the
sum of the two metadata caches is less than the default
metadata cache size.
- For user-defined user cache size, check if the current size is
less than the default user cache size. For either or both user-defined
metadata cache size and metadata backing cache size, check if the
sum of the two metadata caches is less than the
- z/OS® releases the check applies to:
- z/OS V2R1 and later.
- 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 parmlib member used at
IBM Health Checker for z/OS startup. If you just 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 HZSPRMxx can
lead to unexpected results and is therefore not recommended.ADDREPLACE POLICY[(policyname)] [STATEMENT(name)]
UPDATE
CHECK(IBMZFS,ZFS_VERIFY_CACHESIZE)
SEVERITY(LOW)
INTERVAL(ONETIME)
PARM('META_CACHE=size1, USER_CACHE=size2’)
DATE('20150205')
REASON('Your reason for making the update.')Note: The cache sizes (size1 and size2) are the internally-calculated defaults based on the current configuration option settings and the amount of real storage during zFS initialization.For z/OS V2R2 and up, the previous parameter METABACK_CACHE
is no longer supported.
- Debug support:
- No
- Verbose support:
- No
- Parameters accepted:
- Specifying one or more keywords of meta_cache and
user_cache is acceptable. Each keyword defines a
decimal number to be compared with the current cache size. The decimal
number is limited to a length of 10 characters and a maximum value
of 2147483647 (2G-1). A K, M or G can
be appended to the number to mean kilobytes, megabytes or gigabytes,
respectively.
- The valid range for meta_cacheis 1 M through 64G
- The valid range for user_cache is 10 M to 64 G.
PARM('USER_CACHE=1G') /* To override the user_cache_size default */ PARM('META_CACHE=200000000,USER_CACHE=100000K') PARM('META_CACHE=50M, USER_CACHE=100M') - The valid range for meta_cacheis 1 M through
- Default:
- The default is the internally-calculated cache size beginning in z/OS V2R1 based on the current configuration option settings and the amount of real storage during zFS initialization.
- Reference:
- None.
- Messages:
- This check issues the following exception messages:
- IOEZH0044E
- IOEZH0045E
- SECLABEL recommended for multilevel security users:
- SYSLOW - see z/OS Planning for Multilevel Security and the Common Criteria for information about using security labels.