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  1. Home
  2. Veritas NetBackup™ Deduplication Guide
  3. Configuring deduplication
  4. Configuring the Deduplication Multi-Threaded Agent behavior
  5. MSDP mtstrm.conf file parameters
Veritas NetBackup™ Deduplication Guide

MSDP mtstrm.conf file parameters

The mtstrm.conf configuration file controls the behavior of the Deduplication Multi-threaded Agent. The default values balance performance with resource usage.

A procedure exists that describes how to configure these parameters.

The pd.conf file resides in the following directories:

  • (UNIX) /usr/openv/lib/ost-plugins/

  • (Windows) install_path\Veritas\NetBackup\bin\ost-plugins

See Configuring the Deduplication Multi-Threaded Agent behavior.

The mtstrm.conf file is comprised of three sections. The parameters must remain within their sections. For descriptions of the parameters, see the following sections:

  • Logging parameters

  • Process parameters

  • Threads parameters

The mtstrm.conf file resides in the following directories:

  • UNIX: /usr/openv/lib/ost-plugins/

  • Windows: install_path\Veritas\NetBackup\bin\ost-plugins

Logging parameters

The following table describes the logging parameters of the mtstrm.conf configuration file.

Table: Logging parameters (mtstrm.conf file)

Logging Parameter

Description

LogPath

The directory in which the mtstrmd.log files are created.

Default values:

  • Windows: LogPath=install_path\Veritas\pdde\\..\netbackup\logs\pdde

  • UNIX: LogPath=/var/log/puredisk

Logging

Specify what to log:

Default value: Logging=short,thread.

Possible values:

minimal: Critical, Error, Authentication, Bug
short  : all of the above plus Warning
long   : all of the above plus Info
verbose: all of the above plus Notice
full   : all of the above plus Trace messages (everything)
none   : disable logging

To enable or disable other logging information, append one of the following to the logging value, without using spaces:

,thread  : enable thread ID logging.
,date    : enable date logging.
,timing  : enable high-resolution timestamps
,silent  : disable logging to console

Retention

How long to retain log files (in days) before NetBackup deletes them.

Default value: Retention=7.

Possible values: 0-9, inclusive. Use 0 to keep logs forever.

LogMaxSize

The maximum log size (MB) before NetBackup creates a new log file. The existing log files that are rolled over are renamed mtstrmd.log.<date/time stamp>

Default value: LogMaxSize=500.

Possible value: 1 to the maximum operating system file size in MBs, inclusive.

Process parameters

The following table describes the process parameters of the mtstrm.conf configuration file.

Table: Process parameters (mtstrm.conf file)

Process Parameter

Description

MaxConcurrentSessions

The maximum number of concurrent sessions that the Multi-Threaded Agent processes. If it receives a backup job when the MaxConcurrentSessions value is reached, the job runs as a single-threaded job.

By default, the deduplication plug-in sends backup jobs to the Multi-Threaded Agent on a first-in, first-out basis. However, you can configure which clients and which backup policies the deduplication plug-in sends to the Multi-Threaded Agent. The MTSTRM_BACKUP_CLIENTS and MTSTRM_BACKUP_POLICIES parameters in the pd.conf control the behavior. Filtering the backup jobs that are sent to the Multi-Threaded Agent can be very helpful on the systems that have many concurrent backup jobs.

See MSDP pd.conf file parameters.

Default value: MaxConcurrentSessions= (calculated by NetBackup; see the following paragraph).

NetBackup configures the value for this parameter during installation or upgrade. The value is the hardware concurrency value of the host divided by the BackupFpThreads value (see Table: Threads parameters (mtstrm.conf file)). (For the purposes of this parameter, the hardware concurrency is the number of CPUs or cores or hyperthreading units.) On media servers, NetBackup may not use all hardware concurrency for deduplication. Some may be reserved for other server processes.

For more information about hardware concurrency, see the pd.conf file MTSTRM_BACKUP_ENABLED parameter description.

See MSDP pd.conf file parameters.

Possible values: 1-32, inclusive.

Warning:

Veritas recommends that you change this value only after careful consideration of how the change affects your system resources. With default configuration values, each session uses approximately 120 to 150 MBs of memory. The memory that is used is equal to (BackupReadBufferCount * BackupReadBufferSize) + (3 * BackupShmBufferSize) + FpCacheMaxMbSize (if enabled).

BackupShmBufferSize

The size of the buffers (MB) for shared memory copying. This setting affects three buffers: The shared memory buffer itself, the shared memory receive buffer in the mtstrmd process, and the shared memory send buffer on the client process.

Default value: BackupShmBufferSize=2 (UNIX) or BackupShmBufferSize=8 (Windows).

Possible values: 1-16, inclusive.

BackupReadBufferSize

The size (MB) of the memory buffer to use per session for read operations from a client during a backup.

Default value: BackupReadBufferSize=32.

Possible values: 16-128, inclusive.

BackupReadBufferCount

The number of memory buffers to use per session for read operations from a client during a backup.

Default value: BackupReadBufferCount=3.

Possible values: 1 to 10, inclusive.

BackupBatchSendEnabled

Determines whether to use batch message protocols to send data to the storage server for a backup.

Default value: BackupBatchSendEnabled=1.

Possible values: 0 (disabled) or 1 (enabled).

FpCacheMaxMbSize

The maximum amount of memory (MB) to use per session for fingerprint caching.

Default value: FpCacheMaxMbSize=20.

Possible values: 0-1024, inclusive.

SessionCloseTimeout

The amount of time to wait in seconds for threads to finish processing when a session is closed before the agent times-out with an error.

Default value: 180.

Possible values: 1-3600.

SessionInactiveThreshold

The number of minutes for a session to be idle before NetBackup considers it inactive. NetBackup examines the sessions and closes inactive ones during maintenance operations.

Default value: 480.

Possible values: 1-1440, inclusive.

Threads parameters

The following table describes the threads parameters of the mtstrm.conf configuration file.

Table: Threads parameters (mtstrm.conf file)

Threads Parameter

Description

BackupFpThreads

The number of threads to use per session to fingerprint incoming data.

Default value: BackupFpThreads= (calculated by NetBackup; see the following explanation).

NetBackup configures the value for this parameter during installation or upgrade. The value is equal to the following hardware concurrency threshold values.

  • Windows and Linux: The threshold value is 2.

  • Solaris: The threshold value is 4.

For more information about hardware concurrency, see the pd.conf file MTSTRM_BACKUP_ENABLED parameter description.

See MSDP pd.conf file parameters.

BackupSendThreads

The number of threads to use per session to send data to the storage server during a backup operation.

Default value: BackupSendThreads=1 for servers and BackupSendThreads=2 for clients.

Possible values: 1-32, inclusive.

MaintenanceThreadPeriod

The frequency at which NetBackup performs maintenance operations, in minutes.

Default value: 720.

Possible values: 0-10080, inclusive. Zero (0) disables maintenance operations.

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