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Operating System Version Support |
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NOMAD is supported when installed with any
currently supported versions of VM/ESA. |
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Communications |
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Communication between virtual machines is handled
via IUCV. NOMAD uses the documented IUCV interface including CMSIUCV so TSAF
works between systems. NOMAD can be converted to use VMCF by changing one
installation option and re-installing. No application level code needs to
change. |
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Disk Storage |
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Since NOMAD uses standard CMS MACROs and
functions to perform disk I/O, NOMAD supports all disk that CMS supports.
Database blocksizes are determined by the disk blocksize. However, NOMAD I/O can
be optimized by specifying how many blocks are read at one time and/or by
specifying the logical blocksize. In XA and XC virtual machines, most I/O is
done above 16M. |
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Virtual Machine Storage |
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NOMAD requires a minimum of a 1 megabyte virtual
machine. It will use as much storage as needed and is available within the
virtual machine. A run-time option is available to reserve storage for CMS or
called application use. In addition to the virtual machine storage, an
installation can choose to set up special "expansion" segments that
are attached in exclusive writable mode as NOMAD needs additional storage. This
allows normally small virtual machines to obtain additional storage only when
needed. Any attached "expansion" segments are detached upon exit from
NOMAD. |
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Memory Usage |
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NOMAD uses storage above the 16 megabyte line
when it is available. This can be virtual machine storage or
"expansion" segments as described above. The NOMAD shared segment can
be either above the 16 megabyte line or below. If below, NOMAD dynamically
decides whether it is running in a 370 virtual machine or an XA virtual machine. |
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Foreign Language Support |
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NOMAD "knows" certain different foreign
languages and provides error messages, date formats and number formats as
appropriate. The installation can choose to install any or all of the languages,
and can choose to have them available in the shared segment or on a shared disk. |
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Security |
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NOMAD allows several different levels of
security. System profiles, database profiles and user profiles enable
restriction of NOMAD commands and data access. Database passwords are provided
to allow additional security. System profiles and database profiles can be
scrambled or pre-scanned. If desired, the disk containing the system profile
will be dynamically linked and accessed by NOMAD before the user ever gets a
chance to execute anything. After use, the system profile disk can optionally be
detached by NOMAD. User exits are available for database access to provide
additional security. |
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Optimal Resource Utilization |
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NOMAD was specifically developed to run in the
virtual machine environment. It is written in Assembler and C, and is completely
re-entrant. Furthermore, NOMAD takes advantage of VM's Extended Architecture
operating system and runs in exploitation mode, above the 16 megabyte line, with
most temporary storage obtained above the line. In addition, NOMAD is fully
tested and operable in the VM/ESA environment. |
