• You don't want to pay for - or can't afford - a full-fledged Windows
NT server, yet you still need the functionality that one provides.
• You want to provide a common area for data or user directories in
order to transition from a Windows server to a Unix one, or vice
versa.
• You want to be able to share printers across both Windows and Unix
workstations.
• You want to be able to access NT files from a Unix server.
Let's take a quick tour of Samba in action. Assume that we have the
following basic network configuration: a Samba-enabled Unix machine, to
which we will assign the name hydra, and a pair of Windows clients, to
which we will assign the names phoenix and chimaera, all connected
via a local area network (LAN). Let's also assume that hydra also has a
local inkjet printer connected to it, lp, and a disk share named network -
both of which it can offer to the other two machines. A graphic of this
network is shown in Figure 1.1
.
Figure 1.1: A simple network setup with a Samba server
In this network, each of the computers listed share the same workgroup. A
workgroup is simply a group nametag that identifies an arbitrary collection
of computers and their resources on an SMB network. There can be several
workgroups on the network at any time, but for our basic network example,
we'll have only one: the SIMPLE workgroup.
1.2.1 Sharing a Disk Service
If everything is properly configured, we should be able to see the Samba
server, hydra, through the Network Neighborhood of the phoenix
Windows desktop. In fact, Figure 1.2
shows the Network Neighborhood of
the phoenix computer, including hydra and each of the computers that
reside in the SIMPLE workgroup. Note the Entire Network icon at the top of
the list. As we just mentioned, there can be more than one workgroup on an
SMB network at any given time. If a user clicks on the Entire Network icon,
he or she will see a list of all the workgroups that currently exist on the
network.
Figure 1.2: The Network Neighborhood directory
We can take a closer look at the hydra server by double-clicking on its
icon. This contacts hydra itself and requests a list of its shares - the file
and printer resources - that the machine provides. In this case, there is a
printer entitled lp and a disk share entitled network on the server, as
shown in Figure 1.3
. Note that the Windows display shows hostnames in
mixed case (Hydra). Case is irrelevant in hostnames, so you may see hydra,
Hydra, and HYDRA in various displays or command output, but they all
refer to a single system. Thanks to Samba, Windows 98 sees the Unix server
as a valid SMB server, and can access the network folder as if it were just
another system folder.
Figure 1.3: Shares available on the hydra sever as viewed from phoenix
One popular feature of Windows 95/98/NT is that you can map a letter-drive
to a known network directory using the Map Network Drive option in the
Windows Explorer.[ 3
] Once you do so, your applications can access the
folder across the network with a standard drive letter. Hence, you can store
data on it, install and run programs from it, and even password-protect it
against unwanted visitors. See Figure 1.4
for an example of mapping a
letter-drive to a network directory.
[3] You can also right-click on the shared resource in the Network
Neighborhood, and then select the Map Network Drive menu item.
Figure 1.4: Mapping a network drive to a Windows letter-drive
Take a look at the Path: entry in the dialog box of Figure 1.4
. An equivalent
way to represent a directory on a network machine is by using two
backslashes, followed by the name of the networked machine, another
backslash, and the networked directory of the machine, as shown below:
\\
network-machine
\
directory
This is known as the UNC (Universal Naming Convention) in the Windows
world. For example, the dialog box in Figure 1.4
represents the network
directory on the hydra server as:
\\HYDRA\
network
If this looks somewhat familiar to you, you're probably thinking of uniform
resource locators (URLs), which are addresses that web browsers such as
Netscape Navigator and Internet Explorer use to resolve machines across the
Internet. Be sure not to confuse the two: web browsers typically use forward
slashes instead of back slashes, and they precede the initial slashes with the
data transfer protocol (i.e., ftp, http) and a colon (:). In reality, URLs and
UNCs are two completely separate things.
Once the network drive is set up, Windows and its programs will behave as
if the networked directory was a fixed disk. If you have any applications that
support multiuser functionality on a network, you can install those programs
on the network drive.[ 4
] Figure 1.5 shows the resulting network drive as it
would appear with other storage devices in the Windows 98 client. Note the
pipeline attachment in the icon for the G: drive; this indicates that it is a
network drive instead of a fixed drive.
[4] Be warned that many end-user license agreements forbid installing a
program on a network such that multiple clients can access it. Check the
legal agreements that accompany the product to be absolutely sure.
Figure 1.5: The Network directory mapped to the client letter-drive G
From our Windows NT Workstation machine, chimaera, Samba looks
almost identical to Windows 98. Figure 1.6
shows the same view of the
hydra server from the Windows NT 4.0 Network Neighborhood. Setting
up the network drive using the Map Network Drive option in Windows NT
Workstation 4.0 would have identical results as well.
Figure 1.6: Shares available on hydra (viewed from chimaera)
1.2.2 Sharing a Printer
You probably noticed that the printer lp appeared under the available shares
for hydra in Figure 1.3
. This indicates that the Unix server has a printer
that can be shared by the various SMB clients in the workgroup. Data sent to
the printer from any of the clients will be spooled on the Unix server and
printed in the order it is received.
Setting up a Samba-enabled printer on the Windows side is even easier than
setting up a disk share. By double-clicking on the printer and identifying the
manufacturer and model, you can install a driver for this printer on the
Windows client. Windows can then properly format any information sent to
the network printer and access it as if it were a local printer (we show you
how to do this later in the chapter). Figure 1.7
shows the resulting network
printer in the Printers window of Windows 98. Again, note the pipeline
attachment below the printer, which identifies it as being on a network.
Figure 1.7: A network printer available on hydra (viewed from
chimaera)
1.2.2.1 Seeing things from the Unix side
As mentioned earlier, Samba appears in Unix as a set of daemon programs.
You can view them with the Unix ps and netstat commands, you can
read any messages they generate through custom debug files or the Unix
syslog (depending on how Samba is set up), and you can configure it from
a single Samba properties file: smb.conf
. In addition, if you want to get an
idea of what each of the daemons are doing, Samba has a program called
smbstatus
that will lay it all on the line. Here is how it works:
# smbstatus
Samba version 2.0.4
Service uid gid pid machine
network davecb davecb 7470 phoenix
(192.168.220.101) Sun May 16
network davecb davecb 7589 chimaera
(192.168.220.102) Sun May 16
Locked files:
Pid DenyMode R/W Oplock Name
7589 DENY_NONE RDONLY EXCLUSIVE+BATCH
/home/samba/quicken/inet/common/system/help.bmp
Sun May 16 21:23:40 1999
7470 DENY_WRITE RDONLY NONE
/home/samba/word/office/findfast.exe
Sun May 16 20:51:08 1999
7589 DENY_WRITE RDONLY EXCLUSIVE+BATCH
/home/samba/quicken/lfbmp70n.dll Sun May 16
21:23:39 1999
7589 DENY_WRITE RDWR EXCLUSIVE+BATCH
/home/samba/quicken/inet/qdata/runtime.dat Sun
May 16 21:23:41 1999
7470 DENY_WRITE RDONLY EXCLUSIVE+BATCH
/home/samba/word/office/osa.exe
Sun May 16 20:51:09 1999
7589 DENY_WRITE RDONLY NONE
/home/samba/quicken/qversion.dll Sun May 16
21:20:33 1999
7470 DENY_WRITE RDONLY NONE
/home/samba/quicken/qversion.dll Sun May 16
20:51:11 1999
Share mode memory usage (bytes):
1043432(99%) free + 4312(0%) used + 832(0%)
overhead = 1048576(100%) total
The Samba status from this output provides three sets of data, each divided
into separate sections. The first section tells which systems have connected
to the Samba server, identifying each client by its machine name (
phoenix and chimaera) and IP address. The second section reports the
name and status of the files that are currently in use on a share on the server,
including the read/write status and any locks on the files. Finally, Samba
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