Veritas NetBackup™ Administrator's Guide, Volume II
- NetBackup licensing models and the nbdeployutil utility
- Creating and viewing the licensing report
- Reviewing a capacity licensing report
- Reconciling the capacity licensing report results
- Reviewing a traditional licensing report
- Additional configuration
- About dynamic host name and IP addressing
- About busy file processing on UNIX clients
- About the Shared Storage Option
- About configuring the Shared Storage Option in NetBackup
- Viewing SSO summary reports
- About the vm.conf configuration file
- Holds Management
- Menu user interfaces on UNIX
- About the tpconfig device configuration utility
- About the NetBackup Disk Configuration Utility
- Reference topics
- Host name rules
- About reading backup images with nbtar or tar32.exe
- Factors that affect backup time
- NetBackup notify scripts
- Media and device management best practices
- About TapeAlert
- About tape drive cleaning
- How NetBackup reserves drives
- About SCSI persistent reserve
- About the SPC-2 SCSI reserve process
- About checking for data loss
- About checking for tape and driver configuration errors
- How NetBackup selects media
- About selecting media in robots
- About selecting media in standalone drives
- About Tape I/O commands on UNIX
About direct I/O for backups on Windows
By default, the buffer size for disk storage units is 256 KB. If the buffer size is set to a value greater than 256 KB, backups written to that storage unit automatically use direct I/O. An increased buffer size can improve backup speed.
To increase the buffer size, the following conditions must be met:
A Windows media server must own the storage unit.
The storage unit must be either a BasicDisk or an Array Disk storage unit.
The backup to be stored cannot be multiplexed.
The touch file that disables direct I/O must not be present.
To increase the buffer size, create one of the following touch files on the media server that owns the storage unit:
For backups to disk
For backups to disk or tape
If both touch files are present, SIZE_DATA_BUFFERS_DISK overrides the value in SIZE_DATA_BUFFERS. At this time, Veritas recommends that you use SIZE_DATA_BUFFERS_DISK.
Table: Absolute byte values for SIZE_DATA_BUFFERS_DISK, SIZE_DATA_BUFFERS shows the possible values to include in SIZE_DATA_BUFFERS_DISK or SIZE_DATA_BUFFERS.
Table: Absolute byte values for SIZE_DATA_BUFFERS_DISK, SIZE_DATA_BUFFERS
For a data buffer of this size (kilobytes)
Enter this touch file value
Data buffer sizes continue in multiples of 32. Multiply the buffer size by 1024 for the touch file value.
A direct I/O backup triggers the following message: "Enabling direct I/O. Buffer size: <buffer size>."
To disable direct I/O
- Create the following touch file on the media server that owns the storage unit: