NetVault 13.3.2 - Administration Guide

Configuring default settings for tape drives

To configure default settings for a tape drive:

Start a terminal session or command window, and navigate to the “bin” directory under the NetVault installation directory.

Type the following command:

deviceconfig [-servername <FQDN> (-httpport <HTTP port> |
-httpsport <HTTPS port>)] -username <NetVault user>
-password <user password>
‑drivemachine <drive machine name> -drivepath <path to drive>

These options are described in the following table.

Table 158. deviceconfig options for modifying tape drive settings
Option	Description
-servername	Specifies the FQDN, or IP Address of the NetVault Server. With this option, you must specify either the HTTP or HTTPS port to connect to the remote Web Service. If you omit this option, the local server is used. The deviceconfig utility connects to the local Web Service and automatically detects the local Web Service configuration.
-httpport	Specifies the HTTP port for Web Service. This option is only required if the server name is supplied.
-httpsport	Specifies the HTTPS port for Web Service. This option is only required if the server name is supplied.
-username	Specifies a valid NetVault user name.
-password	Specifies the password for the user account.
-drivemachine	Specifies the name of the NetVault machine to which the drive is attached.
-drivepath	Specifies the name or path of the drive.

The deviceconfig utility displays the Drive Configuration screen. You can access the configuration settings by pressing the corresponding option number. The available setting types include the following:

•

NDMP Configuration: To configure NDMP Settings, select this option. For more information about these settings, see NDMP settings.

•

Configuration: To configure general settings for a tape drive, select this option. For more information about these settings, see General settings for tape drives.

•

Software Compression: To configure software compression settings, select this option. For more information about these settings, see Software compression settings.

•

Performance: To configure drive performance settings, select this option. For more information about these settings, see Drive performance settings.

•

Statistics: To configure statistics collection settings, select this option. For more information about these settings, see Statistics collection settings.

•

Generic Cleaning: To configure generic cleaning settings for a tape drive, select this option. For more information about these settings, see Generic cleaning settings.

To save the changes and quit, press s.

(To quit without saving the changes, press q.)

Examples

•

deviceconfig -username default -drivemachine Server-A
-drivepath “Tape fas3020:nrst2a(QUANTUM SDLT320)”

•

deviceconfig -username admin -password mypassword ‑drivemachine Server‑A ‑drivepath “2-0.2.0 (SONY SDX-500C)”

•

deviceconfig -servername 10.11.25.125 -httpsport 8443 -username admin
-password mypassword -drivemachine Client-A
‑drivepath “2-0.2.0 (SONY SDX-500C)”

NDMP settings

On the NDMP Configuration screen, the following settings are available.

Table 159. NDMP settings
Setting	Description
Allow Mover to do Local Data Transfer if Possible	The default setting is OFF. To change it, press the option number.
Allow Mover to do IPC Data Transfers if Possible	The default setting is OFF. To change it, press the option number.
Allow Mover to do TCP Data Transfer if Possible	The default setting is ON. To change it, press the option number.
Allow Mover to do Direct Backup if Possible	The default setting is ON. To change it, press the option number.
Allow Mover to do Direct Restore if Possible	The default setting is ON. To change it, press the option number.
Emulate NDMP Device	The default setting is ON. To change it, press the option number.

General settings for tape drives

On the Configuration screen, the following settings are available.

Table 160. General settings for tape drives

Setting

Description

Device Serial Number

Displays the drive serial number.

End of media warning

This option specifies the amount of media reserved at the end of the tape at which the “end of media” warnings are issued. This value is specified in MB. The default value is 0MB.

Time between polling empty drive

This option specifies the interval at which NetVault polls a standalone drive to detect a tape in the device. This value is specified in number of minutes. The default value is one (1).

To turn off polling, set this option to zero (0).

Media block size (KiB)

This option specifies the block size used for read and write operations. The default value is 64KiB.

You can change the media block size in increments of 1KiB, but many devices may only accept a value in the multiples of 4KiB or 32KiB.

NOTE: The changes to the media block size settings are only applied to blank media items. If you are reusing a media item, blank it first for these changes to take effect.

Increasing the block size can reduce the number of times a backup needs to read data and write it to media. However, large media block sizes do not always imply an overall faster backup. The maximum block size is limited by several factors, such as the OS, SCSI adapter, drive make, drive model, and drive type.

On Linux and UNIX systems, you can increase the media block size for optimum performance.

On Windows, you might be required to change the registry setting MaximumSGList to use block sizes larger than 64KB. Before changing this setting, check that the SCSI bus is only used by the tape devices. If other devices also use the SCSI bus, this registry change might prevent them from working. If you want to apply these changes only to a specific channel on the HBA, consult the hardware vendor.

To change the registry setting on Windows, follow these steps:

Start the Registry Editor.

Open the key [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\ Services\<HBA Vendor>\Parameters (where <HBA Name> is specific to your SCSI card — for example, QL2200 for a Qlogic 2200 card).

Create the Parameters key if not present.

Under Parameters, create the Device key if not present.

Under the Device key, add the DWORD registry value MaximumSGList if not present.

Calculate the hexadecimal value of MaximumSGList:

On 32-bit systems:

MaximumSGList = (Maximum Block Size / 4KiB) + 1

For example, if the block size is set to 256KiB, the value for this key is:

(256KiB/4KiB) + 1 = 65

The decimal value is 65 and the hexadecimal value is 0x41.

You can set the block size to any value from 64KiB through 1012KiB. The maximum value 255 is internally converted to 257 to make a block size of 1 MiB (1024 KiB).

On 64-bit systems:

On 64-bit systems, the default OS page size is 8KiB. The formula for calculating MaximumSGList is:

MaximumSGList = (Maximum Block Size / 8KiB) +1

Thus, the maximum value of 255 corresponds to a maximum media block size of 2MiB.

Reboot the system to apply the changes.

Time to wait for plugin to connect

This option specifies the timeout period for the plug-in to connect to NetVault. The job is aborted if connection cannot be established within the specified interval. This value is specified in number of seconds. The default value is zero (0). With the default setting, the job is not timed out.

Supports Short Reads

The default setting is ON. To change it, press the option number.

Cleaning Tapes Supported

This option indicates whether the library supports cleaning tapes or not. The default value is usually correct, unless certain library models have a different setting.

Compression

This option allows you to use a tape drive’s built-in compression feature. Not all tape drives support hardware-based data compression. The compression ratio varies depending on the type of data and the compression algorithm that the drive uses. Consult the hardware documentation to determine the compression ratios for the drive.

Software compression settings

On the Software Compression screen, the following settings are available. The software compression settings only apply to virtual tape drives.

Table 161. Software Compression settings

Setting

Description

Perform software data compression

The default setting is OFF. To perform software compression, change the setting to ON. The data is compressed when it is transferred to the device during backup.

Compression decision switch

The value set for this option determines the minimum level of compression that must be achieved when data is compressed during a backup. For example, if you set the value to 80 percent, one of the following occurs:

•

If the compressed data size is less than 80 percent of the original data size, the data is backed up in its compressed form.

•

If the compressed data size is more than 80 percent of the original data size, the data is backed up in its uncompressed form.

If you specify 80 percent, a file size of a 100MB must be <= 80MB after compression however, the file size can be >80MB (like 81MB, 82MB, etc.), as the compression is done at block level.

When the specified compression level is not achieved for any block, in that case NetVault backs up that block in its uncompressed form. Where, some blocks may be compressed and some blocks may remain in uncompressed form. Hence, in some case, the file size after compression can be greater than 80 percent.

The extent that data can be compressed depends on the data contents. Also the encrypted data cannot be compressed. With some files, compression may actually result in a file that is larger than the original uncompressed file.

Number of data blocks per compression unit

Type the number of data blocks per compression unit. The default block size is 8KiB.