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Recommended access order (RAO) open function
RAO enables tape control applications to accelerate the retrieval of a certain number of files from a single tape thereby reducing the seek time between
those files.
Archive mode unthread
The drive archive mode unthread feature is designed to fine-tune the media for long term storage by ensuring that the media inside the cartridge is stored at
an optimal tension.
Speed matching
To improve system performance, the drive uses a technique that is called speed matching to dynamically adjust its native (uncompressed) data rate to the
slower data rate of a server.
Channel calibration
System performance is optimized by channel calibration.
Data cartridge capacity scaling
Capacity scaling enables faster random access to data.
Encryption
The LTO tape drive supports host Application Managed Encryption (AME), with T10 encryption methods.
Media optimization
Media optimization is a new feature for the LTO9 tape drive with L9/LZ media.
The increased number of tracks used to write data on tape requires greater precision. Media optimization creates a referenced calibration for each cartridge that
enables the tape drive's intelligent alignment to optimize data placement. LTO-9 media optimization enhances LTO tape long-term media durability.
It is important to consider when media optimization will be performed:
Media optimization will be performed on first load of L9/LZ media during initialization.
Recommendation is to perform first load in the location of deployment, which should be in a stable environment that meets the recommended
environmental specification (see
Media optimization is a one-time operation that can be completed on any drive in the environment, enabling the media to be used across all tape drives
without further optimization.
Other considerations for media optimization:
Media optimization averages 40 minutes per first load of a cartridge to a tape drive. Although most media optimizations will complete within 60 minutes
some media optimizations may take up to 2 hours.
Interruption of the process is not recommended.
A different mount will not necessarily improve the time to complete the one-time optimization.
An update to software may be required. Contact your software application provider for more details. Customized software, not provided as a standard market
product, may require modification to ensure the software can handle the extended first mount time. For additional details, review the detailed section of the
LTO SCSI
Reference.
Recommended access order (RAO) open function
RAO enables tape control applications to accelerate the retrieval of a certain number of files from a single tape thereby reducing the seek time between those files.
A feature of the LTO-9 full-height drives is the ability to accept a list of User Data Segments and reorder those User Data Segments into a recommended access
order that minimizes the locate portion of the time to read those User Data Segments. This sorted list is called a Recommended Access Order (RAO) list. A User
Data Segment (UDS) is defined as a grouping of contiguous logical objects (i.e., logical blocks and filemarks) and is described by partition number, beginning logical
object identifier, and ending logical object identifier.
The RAO implementation in LTO produces the best results for performance enhancement when there is little variability in block size or data compression ratio.
When the variability in compression ratio or block sizes increase, the accuracy of the locate estimates may be reduced and any potential performance
enhancements may be diminished.
Archive mode unthread
The drive archive mode unthread feature is designed to fine-tune the media for long term storage by ensuring that the media inside the cartridge is stored at an
optimal tension.
Tuning to optimal tension requires longer unthread time. The time that is required for an unload depends on how the cartridge has been used during the mount.
This is based on the current position and how far from the beginning of tape (BOT) the media has been moved since mount. For details on unload performance, see
Drive
information.
This feature is available with LTO-7 and later tape drives. For more details, see
Speed matching
84 IBM TS22xx Tape Drives
Environment specifications
for details).
SCSI
Reference.
IBM
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