Installing the server operating system 2. Installing any required drivers Installing any required service packs 4. Installing any required hotfixes or security patches Installing the backup software 6. Installing any required patches to the backup soft
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FIGURE 12.5 Octopus can be used to back up multiple NT servers to a remote location.
We have also addressed the availability issue. If any one of your sites should go down, the data normally stored at that site would still be available. This is because the Octopus target would detect
the server outage and step in for the missing system. Any network still functioning would be able to access the mirrored copy of the shares from the target server. In short, an entire facility could be
swallowed up by the earth, and from a share access perspective, you would never know the difference.
Installing Octopus
Octopus must be installed on every system that will act as an Octopus target or an Octopus source. To begin the installation process, insert the CD into an NT server and launch the Setup executable. This
will produce the Site Select dialog box, shown in Figure 12.6, which prompts you to enter the Microsoft machine name of the system on which you wish to install Octopus. You can type in the
server name as I have done in the figure or you can click the Get button in order to search the network for NT Servers. The Network Sites section of the dialog box allows you to customize the
amount of information that is reported during a Get. Once you have entered the correct server name, click Continue.
FIGURE 12.6 The Octopus Site Select dialog box
Using Get to search the network for NT servers is an extremely slow process. You should type in the server name directly whenever possible
.
You are next prompted to select a path for the program and data files, as shown in Figure 12.7. These
FIGURE 12.7 The Install Paths dialog box
The final dialog box will prompt you for your license key. You need to visit the Qualix Group Web site
http:www.octopustech.com or contact the Qualix Group directly with your product’s serial
number in order to generate a license key. Once you have entered this key, the program files will be copied to your hard drive and you will be prompted to reboot the NT server.
Remember that you must install a copy of Octopus on every NT server that will be acting as either a source or a target
.
Configuring Octopus
When you log on to the NT server and launch the Octopus icon, you will be presented with the Octopus console shown in Figure 12.8. All share replication is configured from the Octopus source,
so if you are not currently sitting at the source’s console, you can connect to the source system by selecting Functions Attach from the console menu. This will produce the same Site Select dialog
box you worked with during the product installation. You can either type in the name of the Octopus source NT server you wish to connect to or use the Get button to search the network for NT Servers
which have Octopus installed. Once you select the source you wish to work with, the console will become active for that system.
FIGURE 12.8 The Octopus console screen
Next you need to add a specification that identifies which information you wish to replicate and to which source. Select Maintenance Add Specification from the Octopus console menu. This will
produce the Specifications screen shown in Figure 12.9. You should first configure your system to replicate all share information. This is performed by selecting the Mirror Shares radio button at the
top of the screen.
Octopus can only mirror unique share names. This means that two Octopus sources sharing the same target must not have any shares with the same name. If they do, one of the shares will be
disabled on the target system in order to avoid conflicts
.
FIGURE 12.9 Replicating shares with the Specifications screen
The Exclude Shares field allows you to specify certain shares that you do not wish to replicate. To save all shares except for the administrative shares, leave this option blank. The Target Site field
allows you to identify the Octopus target where this share information will be saved. Finally, selecting the Synchronize check box will cause this information to be immediately replicated to the
target system. When all of your options are set, click the OK button.
You also need to identify which directories you wish to replicate. This is done by adding another specification, but this time you will select the Mirror Files radio button at the top of the Specification
screen, as shown in Figure 12.10. This activates the Source Spec and Target Spec fields so that directory paths may be entered. You can only specify one directory path per specification. If you
need to replicate multiple directories, simply create additional specifications.
Checking the Sub Tree box will cause Octopus to replicate all directories located under the specified source directory.
FIGURE 12.10 Replicating files with the Specifications screen
You also need to specify a target system and a target directory. This should be the same target system that will hold the shares, but you can locate the directory information anywhere you choose. Once
you have finished, click OK and add shares as required. Your Octopus console screen should now appear similar to Figure 12.11.
The top windows of the Octopus console show that the Octopus source WWW is set up to replicate to the target system
LAB31
. The green traffic lights tell you that these systems are still able to communicate with each other. Under the target systems, you can see all the specifications you have
configured. In this example, we are replicating the share information and the directories
hotfix
and
i386
. The bottom pane shows the current replication status of the specification highlighted in the top pane. In Figure 12.11, you can see that Octopus found and replicated 2,576 files within the
i386
directory. Now that your share and file information is being replicated, you need to tell your Octopus systems
how they should respond when a failure occurs. This is done by selecting Clustering Source Options from the Octopus console screen. This displays the Source Options dialog box, as shown in
Figure 12.12.
FIGURE 12.12 The Clustering Source Options window
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The Timeouts tab allows you to set up communication parameters between the source and target system. The settings in Figure 12.12 tell the source to transmit a heartbeat every 15 seconds. The
target is configured so as not to assume that the source is offline unless 60 seconds pass in which the target receives no heartbeat transmission. These settings help to insure that one or two lost packets do
not trigger the fail over process.
If you click the IP Addresses to Forward tab, you can specify whether the target system should assume the IP address of the source system when it fails. You can even specify multiple network
cards. This insures that systems that use DNS or WINS to locate the source system will be directed to the target system after a failure.
Remember that the target can only assume the IP address of the source if the two systems are located on the same logical network
.
The final tab, Cluster to, allows you to specify the target system. If you have created a specification as we did earlier in this configuration, this value should be filled in for you and should not need to
be changed. Once you have configured your Source Options, you can click OK to save your changes.
Finally, you need to configure the options for your target system. To do this, select Clustering Target Options from the Octopus console screen. This will produce the clustering Target Options
dialog box, as shown in Figure 12.13.
FIGURE 12.13 The Clustering Target Options window
The Options tab lets you configure how the target responds when it needs to stand in for another system. You can define executables or batch processes to run when a target stands in, as well as when
the source returns to operation. You can also specify whether the target should replace its IP address with that of the source or whether it should use both addresses simultaneously. If you click the Take
Over tab, you will see any current sources that this target has taken over.
The Services tab allows you to specify which services should be run on the target system once a fail over has taken place. By default, all services on the target system are restarted when the target needs
to stand in for a source. This allows the Octopus target to assume machine names and IP addresses as required. You can, however, specify that certain services are not to be restarted and even set certain
services to be run only once a fail over takes place.
The Account tab is for entering authentication information. This is only required if the source is a stand-alone server and the target needs to provide a new System ID SID. If the source is a PDC or a
BDC, this information is not required.
The Notification tab allows you to specify who should be notified when the target needs to stand in for the source. An alert can be sent to an e-mail address, to an NT logon name as a pop-up message,
or even to an entire domain.
Once you have finished configuring your target options, click OK to save your changes. Your source and target systems are now configured to provide server-level fault tolerance in case of disaster.
Testing Octopus
In order to show you how a fail over would look to the average end-user, I have configured three Octopus systems for testing. Two of them
www
and
holnt200
are Octopus sources, while the third
lab31
is set up as the Octopus target. Table 12.2 shows the share names being used by each system.
TABLE 12.2:Share Names Used on the Octopus Test Systems
Host Configuration
Shares
www
Octopus source
hotfix, i386 holnt200
Octopus source
accounting, marketing, last_share lab31
Octopus target
none
Each system was set up as described in the “Configuring Octopus” section of this chapter. Once the sources were configured, the systems were allowed to sit until replication was complete. The
replication process took less than 10 minutes. Once this process was complete,
lab31
had a copy of every share located on the two Octopus sources. A Network Neighborhood view of these shares is
shown in Figure 12.14.
FIGURE 12.14
Lab31
with a copy of all shares I then pulled the power plug literally on servers
www
and
holnt200
and allowed one minute to elapse for the target to figure out that these two source systems were offline this was the configured stand-
lab31
had in fact stepped in for
www
and
holnt200
. As shown in Figure 12.15, this process had already been completed. The Added Names field shows us what source systems the target has stepped in for.
FIGURE 12.15 The Target Options Take Over tab
To confirm that the target had stepped in for the source systems, I launched Network Neighborhood from a Windows 95 test system. As shown in Figure 12.16, the client
Hellsfarr
was fooled into thinking that all the servers were still online and functional. Response time for the Neighbor-hood
search was no longer than when the servers were actually online.
FIGURE 12.16
Lab31
standing in for
www
and
holnt200
Finally, both
www
and
holnt200
were checked to insure that the correct share names were associated with the correct systems. As shown in Figure 12.17,
lab31
associated the correct share names with the system
www
. Opening up each share produced the expected list of files.
FIGURE 12.17
Lab31
advertising the correct shares for
www
Summary
I
n this chapter, you saw what disaster prevention and disaster recovery options are available for protecting your network. We discussed network-based disasters and server-based disasters. We also
discussed the importance of testing and documenting your disaster recovery procedures. Finally, you took a look at a product designed to provide redundant-server fault tolerance in an NT server
environment.
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