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Monday, September 25, 2006

 

How to change the port that Network Data Management Protocol uses in Backup Exec for Windows Servers

In Backup Exec (tm) 9.x for Windows Servers, Network Data Management Protocol (NDMP) is used by Backup Exec to communicate with the remote servers. The Backup Exec Job Engine first communicates with the Remote Agent for Windows Servers through a control session using port 10000. This port can be changed, as it might conflict with existing applications in the environment

The following Event ID 2021 may occur in the application log when installing Backup Exec to a server that is already utilizing port 10000 for another application:

Server was unable to allocate a work item n times in the last seconds second

Caution: When changing the port for NDMP, the changes must take place on every server in the environment that needs to be protected by Backup Exec. Failing to do so will result in servers not being selectable inside Backup Exec or not able to be backed up at all.

To change the port, do the following:

On the Backup Exec media server:
1. Open BEUtility (by default, located in C:\Program Files\VERITAS\Backup Exec\NT)

2. From the right pane, select the Backup Exec media server
Note: If it is not listed, then right-click All Media Servers and select New Media Server.

3. Under Services Tasks, select Stop services

4. Click Start | Run, and type NOTEPAD.EXE to start Notepad

5. Click File | Open. Browse to the C:\WINNT\System32\Drivers\ETC directory, and select the Services file.

6. At the end of the document, type NDMP, and then press and type the port that NDMP will use, and then add /tcp. Press to go to the next line (Figure 1).

7. Click File | Save

8. Click File | Exit

9. From BEUtility, under Services Tasks, select Start services


On each remote server:
1. Open Services (from the Control Panel on Windows NT 4.0 or Start | Programs | Administrative Tools for Windows 2000 and Windows 2003)

2. Stop the Backup Exec Remote Agent for Windows Servers service

3. Click Start | Run, and type NOTEPAD.EXE to start Notepad

4. Go to File | Open. Browse to the C:\WINNT\System32\Drivers\ETC directory, and select the Services file.

5. At the end of the document, type NDMP, and then press and type the port that NDMP will use, and then add /tcp. Press to go to the next line.

6. Click File | Save

7. Click File | Exit

8. Start the Backup Exec Remote Agent for Windows Servers service

 

Backups fail to get double the amount of the native capacity recorded to a media, even when hardware compression is being utilized.

Twice the native capacity of a media is usually given as the maximum possible amount of data that could be written to a tape. It should be noted that this figure is rarely achieved. This is due to the varied types of data that are found in most environments. Each data type has its own compression ratio, and, therefore, there is no standard achievable for the total compression ratio that results. For example, database data, executables, and graphics files generally compress the least, and regular text and data files will compress the most.


If hardware data compression is used, then the compression is done by the tape drive. VERITAS Backup Exec (tm) only sends instruction to the tape drive to do compression. If data is not compressing (either because hardware compression on the tape drive is disabled or because the tape drive does not support it), software compression may be used. Software compression, however, consumes additional system resources and media can only be cataloged and restored from with the Backup Exec software.

To enable hardware compression, follow the instructions given below:

1. Right-click on a tape device

2. Select Properties

3. Select the Configuration tab

The method is similar for Backup Exec 9.0 for Windows Servers

If Enable compression appears grayed, the tape drive may not support compression, or the drivers/firmware for the device may need to be updated. Contact the manufacturer of the device for more information.

Backup Exec offers the choice of either hardware or software compression. Software compression may be a viable alternative if poor results are achieved with the use of hardware compression. The use of hardware or software compression can be configured through the Advanced tab within the Backup Job Properties

The following can also affect hardware compression:

1. The tape drive may be trying to compress data that is already compressed. If the data cannot be compressed any further than it already is, the attempt may cause the data to expand. Run a test backup with no compression to compare how much data can be written to the tape media without compression. When using hardware compression, software compression should be turned off, and vice-versa.

2. The system may not be able to keep up with the tape drive. If data is sent to the tape drive at a rate that is either slower or faster than the rate at which the tape drive can write the data to the tape, then the tape device must stop and wait for the computer. Each time the tape drive stops, it writes tracks of undefined data (gap tracks), repositioning the read/write heads for the time when more data becomes available. This causes the tape drive to stop and restart frequently, affecting tape capacity.

3. The tape media may be ready for retirement. When tapes are written to for longer than what the manufacturer recommends, an excessive number of rewrites can occur, causing a reduction in performance and tape capacity. Use a new tape to test compression and confirm that the media is the correct type for the tape drive.

4. The tape drive may need to be cleaned. A buildup of oxidation and debris on the tape heads can cause soft/hard write errors and eventually could cause damage to the tape media and tape drive. Clean the device as per the manufacturer's recommendation and replace the cleaning tape when necessary.

If in doubt about whether the software or the environment is the cause of a reduced media capacity with hardware compression enabled, it is suggested that the services for Backup Exec be stopped in the control panel, and a backup should be performed with the native Windows NT Backup. In most cases, the results should be identical between the two applications.

 

Backup jobs fail with the error "The directory or file was not found, or could not be accessed." when backing up DFS folders with replication turnedon

When Backing up DFS folders with replication turned on, backup jobs will fail. The reason for the failure is that Backup Exec is trying to backup a folder that it should not backup. The problem folder is called "DO_NOT_REMOVE_NtFrs_PreInstall_Directory"

In the Job Completion Status box the final error will be:
0xe00084af - The directory or file was not found, or could not be accessed.
In the Errors box and in the Backup Set Detail Information box the error will be similar to:
"Directory D:\folder1\DO_NOT_REMOVE_NtFrs_PreInstall_Directory was not found, or could not be accessed. None of the files or subdirectories contained within will be backed up."

There are two possible solutions to this problem.

1. If there are a few problem folders:
The "DO_NOT_REMOVE_NtFrs_PreInstall_Directory" does not need to be backed up. Backup Exec should be excluding this folder by default. If there are only a few folders reporting this error simply modify the backup job(s) and deselect all of the "DO_NOT_REMOVE_NtFrs_PreInstall_Directory" folders referenced in the error(s).

2. If there are too many folders to deselect:
A Global Exclude can be created in Backup Exec to exclude the problem folders. To create a Global Exclude in Backup Exec 10.0:
1. Open Backup Exec.
2. Click on Edit | Edit Selection List...
3. Select the default selection list called Excludes and click Edit
4. On the Excludes Properties box click on Insert
5. On the Advanced file selection screen, under the heading of File selection enter the path in the path field and click ok
6. Repeat steps 4 and 5 if more than one path is required

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