Improving ndsd performance by increasing file system cache

  • 3262305
  • 24-Jul-2006
  • 26-Apr-2012


Novell eDirectory 8.7.3 for Solaris
Novell eDirectory 8.7.3 for Linux
Novell eDirectory 8.8 for Solaris
Novell eDirectory 8.8 for Linux


Limitations on the amount of memory the operating system will allocate to eDirectory prevent setting a large enough cache to accommodate many larger dibs.


A 32-bit application is allocated < 4GB of RAM by the operating system.
Approx. 300-400MB of RAM is used for the ndsd application.
Applications that run under ndsd namespace also request memory which would be included in the total allowed to ndsd.
Flaim cache is also included in the memory allowed to ndsd.

If an eDirectory database is 4GB, flaim cache can not; within the OS limits, be set high enough to allow for effective caching of the entire dib. It is recommended that for dibs larger than 700 MB cache be set to an amount < 1 GB since larger amounts of cache do not improve performance and can reduce overall performance.


Testing at Novell has shown that increasing file system cache so that the file system can store the dib in RAM greatly improves performance.

It is suggested for improved performanced that the eDirectory dib directory be place on a Reiser file system and enough RAM be added to the server so that the entire dib plus 2 GB for applications, etc is available to the server.

In this scenerio, the dib cache size in the _ndsdb.ini file should be set relatively small - approximately 300MB.