Netware 4.1

• New features
  • NetWare Directory Services or Novell Directory Services (NDS)
    • a logical database for a network that replaces all the server-specific bindery files of the Novell 3.x individual servers
      • detail on NDS advantages
  • Client software
    • NETx shell is gone. DOS client software is now called the requester
    • Instead of acting like a tiny operating system along side DOS, the new requester works through DOS
      • the requester has a program called VLM.EXE interrupt DOS to request a service
      • the requester uses DOS tables of network attached resources instead of building its own like the old NETx
      • DOS is now the primary redirector, passing network requests to the requester
      • NetWare client functionality can be added or updated incrementally with virtual loadable modules (VLMs)
      • some VLMs depend on other VLMs and must be loaded in a certain order
      • other VLMs are more independent
      • many VLM modules are loaded separately onto the DOS client computer and 'combined' with DOS to offer the following type of combined functionality
        • IPX and NCP protocol stacks
        • TCP/IP and NCP protocol stacks
        • security function calls
        • NDS services
        • file management
        • DOS redirector
        • printer redirection to network print queues
      • the requester can be updated to the Client32 Requester
        • offers more VLM-services
        • uses client PCs memory more efficiently
• Application Service problem of 3.x corrected
  • operating system used to run in the same memory area as NLMs
  • if a NLM had problems it could and did write into the operating systems memory area and crash the whole network
  • NetWare 4.1 introduced ring memory protection
    • areas of memory, called rings by Novell, are separated and protected from other areas
    • the operating system utilizes ring 0
    • all the NLMs can operate in ring 3
    • ring memory protection should not be confused with protected memory as implemented in Window NT or Unix
      • some NLMs must still run in Ring 0 and could crash the operating system
      • is one NLM crashes in ring 3, it could crash all other NLMs in ring 3
• More on NDS
  • defines two types of objects
    • leaf objects (network resources)
      • file servers, users, printers, print queues, database servers, communication servers
    • container objects
      • companies, divisions, and departments
  • NDS structures do not have to perfectly map organizational structures
  • detail on the directory tree
  • detail on context and names