Red Hat 8.1, Command Reference Manual

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Chapter 3. Plug-in Implemented Server Functionality Reference
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This situation will occur only for certain combinations of the database cache size, the size of physical
memory, and kernel tuning attributes. In particular, this situation should not occur if the database
cache size is less than 100 megabytes.
If the Solaris host seems excessively slow and the database cache size is around 100 megabytes or
more, then use the
iostat
utility to diagnose the problem by monitoring the activity of the disk where
the Directory Server's database files are stored. There are three conditions required before resetting
the
nsslapd-db-home-directory
attribute:
• The disk is heavily used (more than 1 megabyte per second of data transfer).
• There is a long service time (more than 100ms).
• There is mostly write activity.
If these are all true, use the
nsslapd-db-home-directory
attribute to specify a subdirectory of a
tempfs
type filesystem.
The directory referenced by the
nsslapd-db-home-directory
attribute must be a subdirectory
of a filesystem of type tempfs (such as
/tmp
). However, Directory Server does not create the
subdirectory referenced by this attribute. This directory must be created either manually or by using a
script. Failure to create the directory referenced by the
nsslapd-db-home-directory
attribute will
result in Directory Server being unable to start.
Also, if there are multiple Directory Servers on the same machine, their
nsslapd-db-home-
directory
attributes must be configured with different directories. Failure to do so will result in the
databases for both directories becoming corrupted.
The use of this attribute causes internal Directory Server database files to be moved to the directory
referenced by the attribute. It is possible, but unlikely, that the server will no longer start after the files
have been moved because not enough memory can be allocated. This is a symptom of an overly large
database cache size being configured for the server. If this happens, reduce the size of the database
cache size to a value where the server will start again.
Parameter Description
Entry DN cn=config, cn=ldbm database, cn=plugins,
cn=config
Valid Values Any valid directory name in a tempfs filesystem,
such as
/tmp
Default Value
Syntax
DirectoryString
Example nsslapd-db-home-directory: /tmp/slapd-
phonebook
3.4.1.11. nsslapd-db-idl-divisor
This attribute specifies the index block size in terms of the number of blocks per database page.
The block size is calculated by dividing the database page size by the value of this attribute. A value
of
1
makes the block size exactly equal to the page size. The default value of
0
sets the block size
to the page size minus an estimated allowance for internal database overhead. For the majority of
installations, the default value should not be changed unless there are specific tuning needs.