Novell EDIRECTORY 8.8 SP3, Руководство администратора, Страница: 544 / 634

544 Novell eDirectory 8.8 Administration Guide
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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
percentage of available memory. Dynamic limits always refer to a percentage of available memory.
The following command examples are all valid in the
_ndsdb.ini
file.
The following is an example dynamic limit of 75% available memory, a minimum of 16 million
bytes, and 32 million bytes for the OS:
cache=DYN,%:75,MIN:16000000, LEAVE 32000000
The following is an example hard limit of 75% total physical memory, a minimum of 18 million
bytes, and a maximum of 512 million bytes:
cache=HARD, TOTAL,%:75,MIN:18000000, MAX 512000000
The following is an example old style hard limit of 8 million bytes:
cache=8000000
The database cache is divided between block cache and record cache. Block cache holds data and
index blocks that mirror the storage on the disk. Record cache holds in-memory representations of
directory objects and attributes. If updating or adding to the directory, use the block cache setting. If
performing mostly reads, use the record cache. It is possible to cause a thrashing condition in both
caches if performing numerous sequential updates without allocating cache size properly. Unless
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.