User Guide

Understanding Server Memory 9
Server Memory Administration Guide
103-000147-001
August 30, 2001
Novell Confidential
Manual 99a38 July 17, 2001
1 Understanding Server Memory
The NetWare
®
server operating system provides increased memory efficiency
with three important features: logical memory addressing, virtual memory,
and protected memory. The following information is a general introduction to
these and other aspects of NetWare's memory architecture.
 “Introduction to NetWare Memory” on page 9
 “Logical Memory Addressing” on page 11
 “Protected Address Spaces” on page 12
 “Virtual Memory” on page 14
Introduction to NetWare Memory
NetWare 6 requires a minimum of 256 MB of RAM and can access up to 64
GB of RAM. After the SERVER.EXE file is loaded, all remaining memory is
assigned to cache memory and Virtual memory, which is available for
NetWare Loadable Module
TM
(NLM
TM
) programs and other processes to use.
The memory allocator will only allocate up to 4 GB of memory to cache
memory and the remaining will be using by the virtual memory system. When
data is stored in cache, it is stored in 4 KB blocks called cache buffers.
Recently used data is kept in cache buffers in case it is needed again. Caching
data speeds processing because data can be written to or read from cache
hundreds of times faster than it can be read from or written to disk.
Cache memory is used for all the server's processing needs, such as the
following:
 Storing volumes' File Allocation Tables (FAT) and suballocation tables
 Storing volumes' directory entry tables