Server User Manual

Database Attributes under cn=config, cn=ldbm database, cn=plugins, cn=config
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3.4.1.15. nsslapd-db-page-size
This attribute specifies the size of the pages used to hold items in the database in bytes. The minimum
size is 512 bytes, and the maximum size is 64 kilobytes. If the page size is not explicitly set, Directory
Server defaults to a page size of 8 kilobytes. Changing this default value can have a significant
performance impact. If the page size is too small, it results in extensive page splitting and copying,
whereas if the page size is too large it can waste disk space.
Before modifying the value of this attribute, export all databases using the db2ldif script. Once the
modification has been made, reload the databases using the ldif2db script.
Parameter Description
Entry DN cn=config, cn=ldbm database, cn=plugins,
cn=config
Valid Range 512 bytes to 64 kilobytes
Default Value 8KB
Syntax Integer
Example nsslapd-db-page-size: 8KB
3.4.1.16. nsslapd-db-spin-count
This attribute specifies the number of times that test-and-set mutexes should spin without blocking.
WARNING
Never touch this value unless you are very familiar with the inner workings of
Berkeley DB or are specifically told to do so by Red Hat support.
Parameter Description
Entry DN cn=config, cn=ldbm database, cn=plugins,
cn=config
Valid Range 0 to 2^31-1
Default Value 0
Syntax Integer
Example nsslapd-db-spin-count: 0
3.4.1.17. nsslapd-db-transaction-batch-val
This attribute specifies how many transactions will be batched before being committed. This attribute
can improve update performance when full transaction durability is not required. This attribute can be
dynamically modified using ldapmodify. For further information on modifying this attribute, refer to
the "Tuning Directory Server Performance" chapter in the Directory Server Administrator's Guide.