Data Centers

Implementing an enterprise backup system with Legato NetWorker

Managing multiple tape drives on multiple servers can be a drag. In this Daily Drill Down, Ron Nutter shows you how to implement an enterprise backup system using Legato NetWorker.

As your network grows, at some point you’ll find that you have a tape backup drive in each server. Managing multiple tape drives on multiple servers can be a time-consuming chore. Fortunately, you can save a lot of time by implementing an enterprise backup system. In this Daily Drill Down, I’ll walk you through the process of setting up Legato NetWorker to perform a basic backup of your network.

Why do I need an enterprise backup system?
With hard drives becoming larger, digital audio tape (DAT) drives are taking longer to back up. Digital linear tape (DLT) drives are another option, although they’re more expensive than their DAT counterparts. However, you can back up more data onto one tape than you can with DAT, and the backup process takes less time.

In addition, you can use a special type of backup drive system called a mini-library. A mini-library houses one or more DLT drives. The system automatically changes tapes on an as-needed basis. A robotic arm loads and unloads tapes from the DLT drive and stores them in a tape magazine.

Legato can be used on a single-server system, but the product really shows its strength on a multiserver, multiservice (NT, NetWare, Oracle, Exchange, etc.) network. This means that you’ll have only one backup system to learn and use.

Designing your network for an enterprise backup
To engineer your network for the proper backup system, you have to know how much disk space needs to be backed up. You also need to know how big a window you have to get everything backed up.

The price of servers has come down, so you may consider adding a server whose sole job is to back up the other servers. In this way, you avoid putting too much of a load on one server. Such an arrangement also lets you restore files without loading down an already busy server to accomplish that task. It’s a good idea to identify a secondary server on which you can install the backup software. That way, you have an option if your designated server is down for an extended period of time.

You may need to modify how the backup server connects to the other servers to perform backups and restores. One fairly inexpensive option is to place an additional 100-megabit network card in each server and build what amounts to a second network that only backup traffic will use. In this way, you can have backup and restore operations running without taking bandwidth away from the users.

At some point, just having an additional network segment on which to run the backup operations won’t be enough—you’ll have the need for speed. Installing gigabit network cards, theoretically, will give you ten times your current speed. If you choose this option, you won’t have to purchase an additional backup drive or a more expensive mini-library containing more than two backup drives. Make sure the mini-library you choose is on Legato’s supported system list.

Installing Legato
When you purchase your copy of Legato, you’ll need to call the company and request the CDs of the Legato products. The CDs should arrive in a couple of days. Alternatively, you can download the products from Legato’s Web site .

You begin the process by installing the Legato client and server components on the server that will be running Legato and to which the tape drives will be connected. In addition, install just the Legato client on all servers that you want to be backed up to what I’ll refer to as the Legato server. Legato differs from other packages in that the backup process can be handled from the server or the client, whereas the restore process is handled at the client level only.

After you install Legato NetWorker on the server, you must complete a licensing process. Your first stop will be Legato’s Web site, where you click the Registration Process link. Legato requires you to obtain a contact and site ID (two separate numbers) before registering your products. After you’ve completed the online registration, you should receive your contact information within a few hours to a couple of days.

Once you have the information, go back to the same registration page and click on the Returning Customer link. Using the contact information Legato sent you, along with the host ID number generated during the installation process, start the process of obtaining the license codes. You must have these codes if you want to use the products past the 30-day evaluation period.

With each of the Legato products or modules you purchase, you’ll find a series of numbers and letters. You’ll enter this string of information, referred to as an enabler code, on the Legato Web site. The code identifies the products you’re registering. You’ll need to register the Legato NetWorker product before getting the license codes for any of the other products.

When you get the license codes, click the Print button in your browser to get a hard copy of the numbers. You’ll also receive an e-mail message containing the same information. After you get these numbers, open Legato NetWorker, click on the server that will be running NetWorker, and expand the Registration icon at the right of the window. Right-click the Registration icon and select Create. Enter your code in the Enabler Code field in the Create Registration window. Then, click OK to create the license object.

You should now see a license object with the same name as the product you’re in the process of licensing. Double-click that object, enter the authorization code you received from the Legato Web site, and click OK. If you double-click the icon again, the expiration date field changes from displaying an expiration date to showing no date.

Creating a backup routine
Setting up a backup job in Legato NetWorker is a bit different than what you’re probably used to. So, you’ll want to do some planning before trying to back up your enterprise network. This preparation involves a little setup work in the Hosts file of each system you plan to back up.

You’ll need a minimum of two entries in your Hosts file. On the server that’s being backed up, list the IP address, short host name (such as MAILSERV), and the long name (for example, MAILSERV.DOMAIN.COM) for the server that’s being backed up and for the server running Legato NetWorker. On the server that’s running Legato NetWorker, include an entry for the network server as well as for each server that will be backed up by this server. Even if you’re running your own internal DNS servers, make sure this configuration work is done.

In the NetWorker administration program, create an entry for each system that you plan to back up. Right-click on the Clients section, and then click Create. When the Create Client window appears, enter the short host name and click OK. When the window closes, you should see a client entry for the system. Repeat this process for each of the systems you want to back up. Remember, Legato NetWorker out of the box supports a maximum of ten servers, so if you plan to back up more than this, purchase a license pack that will allow you to access additional hosts.

There’s one exception: If you plan to back up a specialized server, such as a Microsoft Exchange Server, you’ll need to create multiple client objects, all referencing the same server. In this case, you can have more than ten systems listed under the Client section.

You have to create several types of objects. In the Legato world, you’ll be dealing with:
  • Groups: Controls if and when the servers will be backed up.
  • Schedule: Controls when a group will be processed.
  • Pool: Controls how the tape is labeled and which tape is used to back up which group.

First, create a group to back up the servers with Legato. (Although Legato creates a default group automatically, you can’t change any settings associated with that group.) To begin, right-click the Group icon and select Create. Enter a name in the Name field in the Create Group window. The start time defaults to 3:33. Change this entry to the time you want the backup job to start. Since the time is kept in 24-hour format, if you want to start the backup job at 10:00 P.M. in the evening, you’ll enter 22:00 in the Time field. Click the Autostart drop-down arrow and select Enabled.

Once you create the schedule for this group, select it on this field. Click OK when you’ve finished. It’s a good idea to create a group for each one of the servers you want to back up. That way, you have the option of individually backing up one or more of the servers without having to back up everything. You can make a particular client a member of more than one Client group. On the additional Client groups you create, leave the Autostart field set to Disabled so that you don’t back up the same server more than one time a night.

Next, you create the Pool object. You can edit the Full pool and assign it to the group you just created. I recommend you assign this group to the other Client groups you created earlier so that you don’t have to worry about having the correctly labeled tape in the tape drive.

The last step is to create a Schedule object. This object controls which type of backup (full or incremental) occurs, if any. Begin by double-clicking the Schedule icon, and then double-click the Default schedule. The Edit Schedule Default window will appear, listing the days of the week displayed in a calendar format. Click the Period drop-down arrow and change the view to a week format. (For our example, we’ll do a full backup each day of the week except for Sunday.) Click on each day of the week, and then click the Set Level button.

You’ll see a list of choices. For our example, you’ll need to click Full (for the days of the week other than Sunday) and Skip (for Sunday). Click OK when you’ve finished editing the default schedule.

At this point, you should have a viable backup solution. Right-click the group you created under the Group icon. You should see several options, one of which is a Start option. This option lets you start a manual backup of the group at any time.

With a bit of tweaking, you have the ability to stream multiple backup save sets at once. This process is known as parallelism, or the ability to back up from multiple sources at one time. Open the properties sheet for the client running Legato NetWorker, and specify the number of total backup streams that can run at any given time. You then need to tweak the parallelism setting on each of the backup drives. If you’re using a mini-library, you have to adjust the setting on a device-by-device basis.

By default, Legato will stream only four different backup processes and each drive will stream only four. This means that Legato will never really use anything past the first drive. If you have two drives, make sure that:
  • The parallelism option on each drive is set to 4.
  • The parallelism option on the client icon representing the Legato NetWorker server is set to 8.

Making these changes ensures that NetWorker will be able to handle up to eight jobs at one time, sending four jobs to each backup drive.

Backing up an Exchange Server
The option to back up an Exchange Server at a mailbox level became available only in version 2.0 of the NetWorker Client for Exchange. Once you’ve installed the NetWorker Client for Exchange on the Exchange Server, open it and try to drill down to where you can see the individual mailboxes. If you can’t see them, you probably have version 1.0. Get the updated client and any available service packs for the Exchange NetWorker client, and apply them before proceeding.

You’ll have to create two additional client entries for the Exchange Server. Use the same name as you did for the first Exchange client entry. Once you’ve created those entries, change the Savesets field in the second Exchange client icon to read MSEXCH:DS. MSEXCH:IS should appear on the next line. This setting will back up the Directory and Information store on the Exchange Server. Next, click the Remote tab, enter the short name of the Exchange Server in the Remote Access field, and enter nsrxchsv.exe in the Backup Command field. This information enables NetWorker to call on a separate process to back up special files on the Exchange Server without having to shut down those services on the Exchange Server.

For the third client entry for the Exchange Server, enter MSEXCH:MB in the Savesets field. Enter the short name of the Exchange Server in the Remote Access field on the Remote tab. Also, enter the Exchange admin account and password in the Remote User and Password fields. As with the previous Exchange client object, enter nsrxchsv.exe in the Backup Command field.

At this point, edit the NetWorker Remote Exec Service on the Exchange Server. Have it log into the server using the same user account and password you used when editing the third client icon for the Exchange Server in Network Administrator that’s backing up the Exchange mailboxes. After you click OK, stop and then start the service to effect the changes. You are now ready to back up the Exchange Server.

Don’t worry if you see a series of failure messages when backing up the Exchange Server that specifically lists most, if not all, of the mailboxes on Exchange. This is a small glitch in the reporting process. Legato should have the reporting feature fixed in a future service pack or client update.

Checking the success or failure of a backup routine
There are several ways you can check the success or failure of a backup configuration in Legato. The quick-and-dirty way is to look at the icon for the group you created in NetWorker after a backup. If you see an exclamation point, everything went well. A red X indicates a problem occurred during the backup.

Right-click the group name and select Details to view the results of the last backup. You will see each part of a server (registry, repair disk, drive letter, etc.) that was backed up. You’ll also see problems that occurred during the backup process.

Periodic maintenance
To keep things running on a trouble-free basis, occasionally monitor the time spent on the daily backup jobs. In addition, perform a periodic cleaning of the drives. Some drives will display a light to alert you that a cleaning process needs to be run. Read the documentation that comes with your tape drive. You may be able to clean the drives by inserting a cleaning tape into the drive and then removing it when the drive beeps. If you’re using a mini-library, there may be a built-in option within the drive that runs through the cleaning process. The option will reset an internal counter to indicate that a cleaning cycle has occurred.

Don’t use just any cleaning tape in the mini-library drives. Choose only manufacturer-approved cleaning tapes, and use them only according to the accompanying guidelines. Some cleaning tapes include a slide-in label with boxes you can check off each time you use the tape. Use these check boxes reliably, and order new tapes when the cleaning tapes are about to expire. Look closely at the recommended drive-cleaning interval the drive manufacturer recommends. By viewing the Legato reports, you may find you need to run a cleaning cycle on the mini-library more often than indicated by the clean-drive light on the mini-library. Keep in mind that a little preventive maintenance can go a long way.
The Legato product is sold with no tech support. Your options are to either pay on a per-call basis (expect to spend around $500 for each call during daytime hours) or purchase a support contract. The support contract ranges from $1,000 for a single contact from your company to several thousand dollars for multiple contacts with priority support on an after-hours basis. Getting a support contract gives you easier access to updates that help keep your system running at its best.
As you can see, Legato NetWorker is a very sophisticated backup system, one worthy of an enterprise configuration. I recommend you start slowly, and then start turning up the bells and whistles as you become more familiar with the product. If you’re backing up multiple servers, Legato NetWorker is definitely worth a look.

Ronald Nutter is a senior systems engineer in Lexington, KY. He's an MCSE, a Novell Master CNE, and a Compaq ASE. Ron has worked with networks ranging in size from single servers to multiserver/multi-OS setups, including NetWare, Windows NT, AS/400, 3090, and UNIX. He's also the help desk editor for Network World. If you’d like to contact Ron, send him an e-mail. (Because of the large volume of e-mail that he receives, it's impossible for him to respond to every message. However, he does read them all.)

The authors and editors have taken care in preparation of the content contained herein, but make no expressed or implied warranty of any kind and assume no responsibility for errors or omissions. No liability is assumed for any damages. Always have a verified backup before making any changes.

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