The way in which memory is managed changed significantly with Netware 6.x and this has not been without its problems. The auto tuning capabilities, enabled by default, can be quite aggressive and isn't always the best solution. Monitoring memory usage and manually configuring all the various settings can be a daunting task, but with the help of some useful tools and a few key TID’s the process need not be too intimidating.
Most people will come to the subject of memory tuning because they are encountering a problem, the most common of which are memory fragmentation and memory leaks. When an NLM loads into memory it is assigned to the first available contiguous block of memory, smaller blocks of memory not large enough to accommodate the NLM are not used and accumulate, this is fragmentation. Memory leaks on the other hand are where a NLM is consuming more and more memory and is usually caused by a damaged or badly written NLM - the simplest solution is to obtain an updated or known good version of the NLM to replace it.
To gain a clearer understanding of memory fragmentation I recommend you check out this short tutorial:
TID 10091980 TUTORIAL:
Memory Fragmentation Issue with Netware 6.5
http://support.novell.com/additional/tutorials/tid10091980/
There is also a non multi-media version which is easier to follow when it comes to working through the steps recommended at:
https://secure-support.novell.com/KanisaPlatform/Publishing/308/
3920657_f.SAL_Public.html
Diagnosing memory problems using Novell Remote Manager is discussed in a Novell Connection magazine article “Fine Print - How’s Your Memory? (Connection Magazine - third quarter 2006)” which can be found at: http://www.novell.com/connectionmagazine/2006/q3/fine_print.html
But bear in mind that Novell themselves are unlikely to recommend disabling the automatic memory tuning features of Netware 6.x and setting manual values, you may have to make the judgement for yourself and there are two Cool tools which are a godsend for that :
SEG.NLM: NetWare Memory Analyzer
http://www.novell.com/coolsolutions/tools/14445.html
This NLM monitors and logs key memory statistics to a file, SEGSTATS.TXT in your sys:system folder.
Memory Tuning Calculator for NetWare 6.5
http://www.novell.com/coolsolutions/tools/16991.html
MEMCALC was written by Hamish Speirs, a Novell volunteer SysOp and there are a number of versions, including an NLM. This excellent utility reads the SEGSTATS.TXT and produces recommended memory configuration changes which you can have it apply for you.
Couple of things to note about using the above:
1.) The server should have been running ideally for several days under normal workloads in order for the statistics gathered to be representative.
2.) Implementing these memory changes will involve switching off automatic memory tuning.
3.) The server will need to be rebooted for the memory changes to take effect.
4.) In the event of needing to contact Novell technical support in relation to memory problems the first thing they will ask you to do is re-implement automatic memory tuning.
I have had excellent results using these utilities and I highly recommend them.
Finally there is a Novell Cool Solutions Wiki on memory tuning which should the latest information:
http://wiki.novell.com/index.php/Memory_tuning_on_NetWare_65
