to keep the tape drive working at optimum performance.
•Tape media type
The data cartridge should match the specification of the tape drive. A lower specification will have a lower transfer speed (see “Data cartridges” on page 27). Use Ultrium 800 GB or Ultrium 800 GB WORM cartridges with Ultrium 960 tape drives, Ultrium 400 GB cartridges with Ultrium 460 tape drives and Ultrium 200 GB cartridges with Ultrium 230 tape drives.
•Data and file types
The type of data being backed up or restored can affect performance. Typically, small files incur greater overhead in processing and access than large files. Equally, data that is not compressible will always limit the speed at which the drive can write/read data. You will achieve no more than native rates with uncompressible data.
Examples of files that compress well are plain text files, spreadsheets; those that compress poorly are those that are either compressed as part of their format (such as, JPEG photographic files) or stored as compressed (such as, .ZIP files or .gz/.Z files on Unix platforms).
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