1    ASU Overview

The Advanced Server for UNIX (ASU) software is a Tru64 UNIX layered application that allows you to share UNIX based file systems and printers with Windows users as shares. Windows users connect to shares without modification to their software. Once connected, the file system or printer associated with a share appears as a transparent extension to a Windows user's local computing environment.

This chapter describes:

1.1    ASU Server Overview

Each system on which you install, configure, and run the ASU software becomes an ASU server. An ASU server provides Windows users with access to UNIX file systems as disk shares and printers as printer shares.

The ASU server provides flexible disk and printer share security by enforcing either the Windows NT security model exclusively, or Windows NT combined with Tru64 UNIX security models. By default, the ASU server implements the Windows NT combined with Tru64 UNIX security model. This security model requires that a Window user have the following user accounts:

An ASU server interoperates with and uses features of the Tru64 UNIX operating system, including preemptive multitasking, symmetric multiprocessing, and time-sharing. The way in which the ASU server interoperates with the Tru64 UNIX operating system software depends on the values assigned to value entries stored in a database called the ASU registry.

An ASU server participates in a Windows domain as a Primary Domain Controller (PDC), Backup Domain Controller (BDC), or member server to provide Windows NT Advanced Server Version 4.0 services described in Table 1-1 to Windows users, clients, and servers.

Table 1-1:  ASU Services

Service Description

Alerter

Used by the ASU server and other ASU services to notify selected users and computers of administrative alerts that occur on this computer.

Browser

Maintains an up-to-date list of controllers in a domain, and provides the list when requested.

EventLog

Records system, security, and application events in the event logs, and enables remote access to those logs.

NetLogon

Verifies the domain user name and password of each person who attempts to log in to the domain or to the ASU server.

Netrun

Lets users run UNIX system applications on a server from their workstation.

Replicator

Replicates directories and the files in those directories to other workstations.

Server

Provides file, print, named pipe sharing, and support for remote procedure calls.

TimeSource

Identifies a controller as the time source for a domain. Other controllers synchronize their clocks with the time server.

1.2    The ASU Server Process Model

The ASU server and client workstations communicate by using the Server Message Block (SMB) protocol, the native file-sharing protocol in the Microsoft Windows and OS/2 operating systems.

The client sends an SMB request to the ASU server. The ASU server receives the SMBs, maps the requests to equivalent Tru64 UNIX system semantics, interprets the client's intent, and performs the Tru64 UNIX system function to satisfy the client's request. The network architecture layers, such as transport and hardware, ensure reliable SMB exchange.

The ASU server is a combination of the system processes that work in close cooperation. The lmx.ctrl process is the ASU master control process and must be running. The UNIX network listener service passes new ASU client connection requests or sessions to the lmx.ctrl process. The lmx.ctrl process accepts a new client session and distributes it to an lmx.srv process. The lmx.srv process actually services the needs of the client.

Figure 1-1 shows the relationship of the network listener service, the lmx.ctrl process, the lmx.srv process, and clients.

Figure 1-1:  ASU Process Model

The number of lmx.srv processes that are created varies according to the number of client sessions. The ASU process model allows multiple client sessions to be serviced by a single lmx.srv process. The lmx.ctrl process determines if a new client session is serviced by an existing lmx.srv process or by a new lmx.srv process. This distribution of client sessions to lmx.srv processes enables more than one client request to be processed at a time.

1.3    The ASU Server Architecture

The ASU server sends SMBs on the network using the NetBIOS protocol on an Ethernet, FDDI, or Token Ring network adapter as supported by the Tru64 UNIX operating system software. The NetBIOS protocol is responsible for establishing logical names for workstations on the network, establishing sessions between workstations' logical names on the network, and supporting reliable data transfer between them.

The ASU software provides and uses the NetBIOS protocol over the following transports:

Figure 1-2 shows the ASU architecture. The ASU software provides the shaded components.

Figure 1-2:  ASU Network Architecture

1.4    ASU Server Administrative Interfaces

To administer the ASU software you can use the following:

1.4.1    ASU Commands

The ASU commands are Tru64 UNIX style commands that you can use to display information about, administer, and troubleshoot the ASU server and domain. You enter ASU commands in lowercase at the Tru64 UNIX command prompt on a system running the ASU software. See the ASU Installation and Administration Guide for more information on ASU commands.

1.4.2    net Commands

The net commands are Windows style commands that you can use to create shares, domain user accounts, and groups and to display information about and administer the ASU server, domain, shares, domain user accounts, and groups.

A net command begins with the word net followed by a keyword and options. You enter net commands in lowercase at the command prompt on a system running the ASU software in the following form:

# net keyword [/option]

See the ASU Installation and Administration Guide for more information on net commands.

1.4.3    Tru64 UNIX Commands and GUIs

The Tru64 UNIX user and file system commands and GUIs provide additional ASU related options that you can use to create and administer shares and domain user accounts. See System Administration for information on administering the ASU server using Tru64 UNIX commands and GUIs.

1.4.4    Windows GUIs

You can use the following Windows based GUIs to administer the ASU server and domain:

You can administer the ASU server by using the version of the Windows GUIs that are provided with a Windows NT Server Version 4.0 and a Windows 2000 Server. For a system running another type of Windows operating system software, you must install the version of the Windows GUIs that are provided with the ASU software. See the ASU Installation and Administration Guide for more information on installing the Windows based GUIs.