Novell EDIRECTORY 8.8 - GUIDE, Руководство пользователя, Страница: 496 / 574

Maintaining Novell eDirectory 497
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system as needed. The database uses a cache pool that is defined by parameters detailed below.
Usually, the more database cache given to eDirectory, the better the performance. However, because
eDirectory uses available system memory for its buffers, if clients are performing queries that
require large data sets to be returned, the size of the database cache might need to be decreased to
have enough system memory for the directory to handle building the query responses.
The database engine uses the database cache to hold the most recently accessed blocks. This cache is
initially defined with a fixed size of 16 MB. The size of this cache can be changed from the
command line in shipping versions of eDirectory. The following example command will set the
eDirectory database cache to 80 million bytes:
set dstrace=!mb 80000000
You can also define a file named _ndsdb.ini in the
sys:\_netware
directory on a NetWare
server, or in the directory containing the eDirectory database files on the Windows (normally
install directory \nds\dbfiles
) and Linux and UNIX environments (normally
\var\nds\dib
). This text file simply needs to contain a line such as the following:
cache=80000000
Don’t add any white space around the equals (=) sign
The cache in eDirectory 8.8 can be initialized with a hard limit just as with earlier versions. In
addition, the upper and lower limits can be set either as hard numbers or as a percentage of available
memory. Dynamic allocation control parameters allow the cache size to grow or shrink depending
on use. If the proper configuration parameters are set, the database cache dynamically grows or
shrinks based on other system resource needs.
Editing the _ndsdb.ini file can manually control database memory usage. The format for INI file
commands is given below:
cache= cacheBytes # Set a hard memory limit
Alternative formats are shown in the following table:
If a hard limit is specified and the administrator wants to define the database cache to use a
percentage of the memory, the administrator can select between a percentage of total memory or a
Command Description
cache= cache_options Sets a hard limit or dynamically adjusting limit. Multiple cache
options can be specified in any order, separated by commas. All
are optional. They are as follows:
DYN or HARD Dynamic or hard limit.
AVAIL or TOTAL These only apply if a hard limit was chosen. Omit these options
for a dynamic limit.
%: percentage The percentage of available or total physical memory.
MIN: bytes The minimum number of bytes.
MAX: bytes The maximum number of bytes.
LEAVE: bytes The minimum number of bytes to leave for the OS.
blockcachepercent= percentage Splits the cache between the block and record cache.