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CNS News
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To: CNS Customers of the z/OS BULK, USER, WORK and TEMP DASD
As we announced in the CNS News Item N0450, CNS has installed a new IBM DS8100 storage subsystem for z/OS which has been configured with 3390-9 (9GB) virtual volumes for mainframe disk data sets, providing enhanced capacity with greater reliability and performance. The new volumes are available for use now and we encourage customers to assist with this move using the following directions. Instructions at the end of this message describe how to begin using the 3390-9's and include some warnings about the move.
As an incentive for CNS customers, all data moved to the 3390-9's from the old pools will not be charged for space through the end of March (FREE!). Normal charges resume on April 1. As soon as you are ready to start using the new DASD (and saving money) please help us by moving your data sets to the new 3390-9 DASD volumes.
We have a staged plan for moving CNS DASD customers.
NOW Customers who want to exploit the improved performance and
to save money may move their data sets to the new 3390-9's.
All new allocations have been directed to the new volumes
unless the user forces allocation on the old volumes by
explicit volser references in JCL or control statements.
CNS has already begun moving some user data sets to the new
devices, but only non-VSAM data sets due to problems
described below.
Feb 26 We will begin forced pooling of all new allocations onto the
new 3390-9's, overriding user specification of the old
volumes. A WARNING message will be written to the batch job's
log informing you to correct the JCL or control statement.
Some jobs specifically referencing the old volumes by
explicit volume serial may fail (for example,
IUTPROGM/IEHPROGM allocation and catalog or IEHLIST listing).
April 2 Any allocations onto the old volumes will result in the
job failing with an ERROR message.
April 16 Any remaining data sets on the old bulk volumes will begin to
be moved to the new volumes on a "best effort" basis. Some data
sets, especially VSAM data sets with alternate indices with
multiple paths, may possibly be lost.
**If you have VSAM data sets with alternate indices with multiple paths
you should move your data sets before April 16.**
May 2 The old bulk volumes will be removed from the system.
WORK05, TEMP04 and TEMP05 will be removed from the system.
Customers should not specify explicit volume serials but rather allow Allocation Control Center (ACC) to direct the allocations to the new volumes.
Your cooperation is greatly appreciated in this move to more reliable and better performing hardware.
CNS uses the product Allocation Control Center (ACC) to manage disk volume selection for users. The conversion of disk drives requires that certain precautions be taken when allocating new disk data sets using the automatic volume selection facilities provided by ACC.
During this conversion from 3390-3 to 3390-9 disk drives we recommend that any VSAM data sets and their alternate indices should be deleted and re-allocated on the new volumes. This should prevent problems with the data set and alternate index being moved using data set copying utilities, which may have problems moving these data sets.
CNS uses the product ACC to maintain several different sets, or pools, of DASD volumes. In the past, different pool names have been used to specify which volumes should be used for allocating new data sets. CNS recommends the use of the pool name "ANY" in the place of a specific volume serial or one of the other pool names. ACC will then select the proper pool based on the data set name high-level index.
You can request disk space for a new data set using the automatic volume selection facilities of ACC to select a DASD volume without having to know which volumes are available in a given pool. This allows for the use of newly added volumes without any user JCL changes.
When a new data set is allocated, ACC uses the high level index of the data set to select the pool of DASD volumes to be used. This facility is used by not specifying a volume serial in the JCL or by specifying VOLUMES(ANY) for a new VSAM data set. The following examples show how to use ACC to select a volume:
- In JCL, use //ddname DD DSN=index.user.dataset,DISP=(,CATLG),
// UNIT=SYSDA,
// {other parameters}
- For VSAM, use DEFINE CLUSTER ( NAME (index.user.dataset) -
RECORDS ( primary secondary ) -
VOLUMES ( ANY ) -
{other parameters} )
Not specifying a volume serial or coding the volume serial "ANY" allows ACC to direct the space request to volumes in the pool associated with the data set name high level index. CNS maintains a table of which pool should be used for a given high level index.
Serious problems can occur if a VSAM data set has multiple paths for an alternate index. The utilities available to CNS to move data sets can not properly move such data sets, and may result in the data becoming unusable or lost. CNS strongly recommends that customers with VSAM data sets that have alternate indices or paths unload, redefine and reload the VSAM cluster themselves during this conversion effort.
Customers that have Direct Access (DA) or "unmovable" data sets should also use the proper utilities to transfer their data to the new volumes.
If you have concerns about these changes or have questions about our new storage subsystem, please contact us at 352-392-2061, or by email at consult@lists.ufl.edu.