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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.
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.
With speed matching, the drive operates at different speeds when it is reading or writing the Ultrium 8 or later cartridge format. Native data rates are shown in the
table.
Speed matching data rates (MB/sec) 408
*
Full height drives only. Maximum native date rate for full height drives is 400 MB/s, and for half height drives is 300 MB/s.
If the server's net (compressed) data rate is between two of the preceding native data rates, the drive calculates the appropriate data rate at which to operate.
Speed matching dramatically reduces backhitch, the condition that occurs when a tape stops, reverses, and restarts motion. A backhitch is usually the result of a
mismatch between the data rates of the server and the drive.
Channel calibration
System performance is optimized by channel calibration.
System performance is further optimized by a feature that is called channel calibration, in which the drive automatically customizes each read/write data channel
to compensate for variations in such things as the recording channel 's transfer function, the media, and characteristics of the drive head.
Data cartridge capacity scaling
Capacity scaling enables faster random access to data.
The SET CAPACITY SCSI command enables a customer to capacity scale a data cartridge to enable faster random access. As an example, a customer can capacity
scale a data cartridge to 20% of its normal length that improves the average access time by almost a factor of 5. However, it also reduces the native capacity of the
tape to 1.2 TB.
Encryption
Data encryption is supported by LTO Ultrium 4 and later data cartridges only.
The IBM® LTO tape drive supports host Application Managed Encryption (AME), with T10 encryption methods.
The encryption-enabled drive contains the necessary hardware and firmware to encrypt and decrypt host tape application data. Encryption policy and encryption
keys are provided by the host application. A drive digital certificate is installed at manufacturing time. Each drive receives a unique serial number and certificate.
The T10 Application can validate each drive instance by checking the drive's digital certificate.
Table 1. Performance parameters
Ultrium Generation Media
Generation 9 media Generation 8 media Generation 7 media
*
*
365.0
*
*
385
341.0
*
*
366
318.0
*
306.4
347
*
273.0
325
*
249.5
305
284
226.0
263
203.0
244
180.0
223
157.5
203
135.0
177
112.0
306.0
287.52
268.56
250.66
231.86
213.06
194.26
175.46
157.67
138.52
120.11
101.46
IBM
IBM TS22xx Tape Drives 5
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