*4 Limiting the I/O inclusion of single VM2000 guest systems (IOLVM)
*4 Less important guest systems that have intensive I/O activity,
*4 can severely impede other, much more important guest systems
*4 that use the same I/O resources.
*4 The IORM function can detect such conflict situations and
*4 intervene predictively. To do this, IORM continuously collects
*4 the utilization values for all known I/O devices, checks the
*4 settings for IOLVM and intervenes in the control if necessary.
*4 IOLVM only considers disk devices. As with the IOPT function,
*4 FDDRL, ARCHIVE, VOLIN and PAGING I/Os are not braked.
*4 Adapting the compression of LTO devices (TCOM)
*4 To ensure optimum data backup to LTO tapes, a minimum data rate
*4 must be maintained to keep the tapes continuously streaming.
*4 This minimum data rate is sometimes only achieved if the
*4 compression is disabled on the device. However, this reduces the
*4 tape capacity accordingly. By default, the compression is always
*4 enabled in
*4 The compression can be fully disabled with the TCOM function.
*4 TCOM can also dynamically enable/disable the compression
*4 according to the data rate. The compression is disabled if the
*4 data rate is sufficient for tape streaming without compression
*4 but not with it.
2.16.2 Support for conversion from 7 bit to 8 bit character set
*4 By default, BS2000/OSD uses the 7 bit EBCDIC character set
*4 EDF03IRV with 95 printable characters and 65 control characters
*4 in the system. The designation 7 bit has established itself
*4 since the reproducible characters available correspond to the
*4 ASCII 7 bit character set although 8 bits are used for coding.
*4 Via the XHCS (Extended Host Code Support) subsystem, BS2000/OSD *4 supports both the 7 bit and 8 bit character sets that encompass *4 128 or 256 characters respectively.
*4 This allows BS2000/OSD to depict all languages that are defined
*4 in the international code tables as per ISO 8859. The concept of
*4 "coded character sets" (CCS) that defines the character coding
*4 in a file is used to depict the different character sets and
*4 codes. The programs get the information about the character sets
*4 from XHCS and do not have to store it themselves. Regardless of
*4 the input source, XHCS identifies the character sets via their
*4 character set names, the
*4 available in the form of tables.
*4 The class 2 option HOSTCODE=<CCS name> can be used to define a
*4 different, specific 8 bit EBCDI code instead of EDF03IRV for the *4 complete BS2000/OSD system. Code definition via the CCS name is *4 possible for separate IDs and pubsets.
*4 The default value for inputs on the terminal to TIAM, UTM and
*4 DCAM applications can be modified globally via the
*4 parameter file
*4 parameters are set, the character set of the home pubset for
*4 this ID apply. This is done for a single process with the command
*4 MODIFY-TERMINAL-OPTIONS CODED-CHARACTER-SET=*8BIT-DEFAULT.
*4 If data is converted from a 7 bit character set to an 8 bit one,
*4 the converted data must be distinguishable from the unconverted
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