Planning your system configuration
Modes of usage
LTO Ultrium tape drives and arrays can be used in different system configurations. They can be used in a
standalone (direct attach) or a SAN.
Network users may need to take additional steps to ensure that their system is configured for optimum
performance.
Optimizing performance
Various factors can affect tape drive performance, particularly in a network environment or if the drive is
not on a dedicated bus. If your tape drive is not performing as well as expected, consider the following
points before contacting Hewlett Packard Enterprise Support at http://www.hpe.com/support/hpesc.
System performance
Drives can write data at 300 MB/s (native) or up to 700 MB/s and at higher speeds with compressible
data. However, to get this performance it is essential that your whole system can deliver this performance.
Typical areas where bottlenecks can occur are:
• Disk system (a single hard disk drive will not be able to deliver required transfer rates).
• Some file systems are able to transfer data faster than others.
• The type of data being backed up can affect backup performance (for example, file sizes and
compressibility).
• Some backup software performs better than others.
To improve performance, you may like to consider a RAIDed disk solution with many physical hard disks.
Some enterprise class backup applications can be made to interleave data from multiple sources, such as
clients or disks, to keep the tape drive working at optimum performance.
Data rate matching
Data Rate Matching (DRM) enables the drive to "stream" data at variable tape speed, which means that it
maintains a continuous data flow to tape even when the transfer speed from the host varies. DRM is
automatically managed by the drive to keep the drive running at best performance. When using Ultrium 8
cartridges, the drive is able to keep streaming between 100 MB/s and 300 MB/s (native). If possible, data
transfer should remain within this range. In most cases, the backup application will provide details of the
average time taken at the end of the backup.
NOTE:
For optimum performance, always use Ultrium 8 30.0 TB (2.5:1 compression) cartridges.
Performance checklist
The following list summarizes factors that can affect performance. They provide guideline only of areas
that may need further investigation. They do not attempt to explain how to configure individual systems.
For a more detailed discussion, including information about tools that allow you to test performance, refer
Planning your system configuration 39
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