Optimizing Edirectory Cache - Novell EDIRECTORY 8.8 SP2 - ADMINISTRATION Manual

18.2.2 Optimizing eDirectory Cache

Novell eDirectory uses persistent caching so that changes being made to a server are held in a
vector. If the server crashes in the middle of changes, eDirectory will load faster and synchronize the
changes in seconds when the server is brought back up. Novell eDirectory uses a rollback model
with a log file to roll forward transactions in the event of a system failure.
eDirectory settings begin with 16MB of cache, 50% of which is allocated to block caching and the
other 50% is allocated to record cache. After 15 minutes, eDirectory will modify its cache thresholds
to initialize up to 51% of the available free memory for the cache, leaving at least 24 MB for the OS.
This algorithm is used only if the host OS supports the call that enables you to determine the amount
of free memory available.
You can optimize your eDirectory cache in the following ways:
For more information on optimizing eDirectory cache, refer to
Performance," on page
Using a Fixed Amount of RAM for Linux and UNIX Systems
Although the above algorithm works well for Windows and NetWare, it does not work as well for
Linux and UNIX systems. On Linux and UNIX systems, the free available memory reported by the
OS will be less than other operating systems because of the way the Linux and UNIX uses free
memory for internal caching of file system blocks, frequently run programs, libraries, etc. In
addition to this memory allocation, libraries on Linux and UNIX normally do not return the freed
memory back to the OS.
For these reasons, we recommend allocating a fixed amount of RAM to the cache.
Fix the amount of RAM for Linux and UNIX systems by doing one of the following:
Manually Creating a .ini File
1 Create a file called _ndsdb.ini in the same directory that the eDirectory database files (DIB
2 Add the following parameters listed in to the _ndsdb.ini file:
534 Novell eDirectory 8.8 Administration Guide
"Using a Fixed Amount of RAM for Linux and UNIX Systems" on page 534
"Setting Cache Parameters" on page 536
548.
"Manually Creating a .ini File" on page 534
"Using Novell iMonitor" on page 535
set) are located (usually in /var/opt/novell/eDirectory/data/dib).
Parameter
blockcachepercent=50
cacheadjustinterval=15
cachecleanupinterval=15
cache=16777216
Description
Sets the percentage of cache that is allocated to caching database
blocks.
Sets the time (in seconds) in which eDirectory will evaluate its
utilization of free memory and adjust the overall cache size.
Sets the time (in seconds) in which eDirectory will write dirty cache
blocks to disk.
Sets the hard limit (in bytes).
Section 18.5, "Improving Bulkload