IBM OS/390 User Manual
VM/ESA distribute that communication capability among the guest images using
virtual channel to channel devices. Similarly, any DASD that is shared between
the VSE LPAR(s) and the VM/ESA LPAR can be defined through R/O minidisk
definitions owned by a place holder virtual machine, and accessed through R/O
links from the OS/390 guests.
virtual channel to channel devices. Similarly, any DASD that is shared between
the VSE LPAR(s) and the VM/ESA LPAR can be defined through R/O minidisk
definitions owned by a place holder virtual machine, and accessed through R/O
links from the OS/390 guests.
26.3.3.3 The Advantages of Guest Support in VM/ESA
You can use
Guest Support in VM/ESA to develop, maintain, manage, and
migrate
other operating systems that make use of one of IBM
′
s 370, 370-XA, or
ESA architectures. System programmers and application programmers often
solve the problems they encounter by using the solutions already integrated or
implicit in VM/ESA. Some of the reasons customers use VM/ESA Guest Support
to run their VSE and/or MVS(OS/390) systems are:
solve the problems they encounter by using the solutions already integrated or
implicit in VM/ESA. Some of the reasons customers use VM/ESA Guest Support
to run their VSE and/or MVS(OS/390) systems are:
•
System Simulation
•
Performance benefits
•
Reduced hardware and migration cost
•
Operations management
•
Recovery management
•
Interactive Computing, Application Development and Support
•
Interactive program development tools
•
Debug and trace tools
•
Interactive data analysis and reduction
•
Access to VM/ESA CMS applications
•
Server consolidation
•
DB2 guest sharing
•
3990 models 3 and 6 Fast Write Transparency
•
Multiple 3270 Session Support
System Simulation
Every computer user has a requirement for a spare system to migrate/upgrade
to a new release, try out a new idea or to isolate, debug and test fixes or
develop and test new production applications. VM/ESA makes virtually unlimited
“spare systems” available in virtual machines, each simulating a real machine
with very high fidelity. The advantages of making one system look like many
need hardly be explained here, but in the present context it is worth mentioning
some of them:
to a new release, try out a new idea or to isolate, debug and test fixes or
develop and test new production applications. VM/ESA makes virtually unlimited
“spare systems” available in virtual machines, each simulating a real machine
with very high fidelity. The advantages of making one system look like many
need hardly be explained here, but in the present context it is worth mentioning
some of them:
•
With VM/ESA
′
s Guest Support Virtual Machine(s) you can create an exact
replica of your production system on which you can test your new programs,
services, and procedures. VM/ESA
services, and procedures. VM/ESA
′
s Guest Support Virtual Machine is an
extremely cost effective way to have your own test system (or as many as
you
you
′
d like). It is also a safe way to test new function because with VM/ESA
′
s
Guest Support, your test system(s) are contained within a guest virtual
machine and securely isolated from your real production system,
applications, and data.
machine and securely isolated from your real production system,
applications, and data.
•
Guest Support gives you the flexibility to create a migration plan that fits the
needs and schedules of your business. This allows your production systems
to remain up during normal business hours, eliminates the work required to
schedule, bring down and restore the production system when off-shift work
is required. Also, the need to schedule and pay for off-shift programming is
eliminated.
needs and schedules of your business. This allows your production systems
to remain up during normal business hours, eliminates the work required to
schedule, bring down and restore the production system when off-shift work
is required. Also, the need to schedule and pay for off-shift programming is
eliminated.
•
You can create a multiple production system environment. For example, your
installation might run VSE applications, be migrating to OS/390, and have a
installation might run VSE applications, be migrating to OS/390, and have a
426
VSE to OS/390 Migration Workbook