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Chapter 14. Data migration in zSeries environments 315
When a level is reached where no data moves any more because the remaining data sets are
in use all the time, some down time has to be scheduled to perform the movement of the
remaining data. This might require you to run DFSMSdss jobs from a system which has no
active allocations on the volumes which need to be emptied.
14.5 z/VM and VSE/ESA data migration
DFSMS/VM® provides a set of software utility and command functions which are suitable for
data migration.
DASD Dump Restore (DDR) provides a physical copy and is suited to copy data between
devices with the same device geometry. DDR cannot be utilized for a device migration, like
from 3380 to 3390.
DIRMAINT CMDISK command moves data between minidisks in VM from any device type
to any device type which is supported by VM.
CMS COPYFILE command offers a logical copy on a file level from any minidisk device to
any minidisk device which VM supports and is suited to migrate to a different device type.
Another logical migration approach is possible through the CP PTAPE command. PTAPE
dumps spool files to tape and then re-loads these files back onto the new disk storage.
Last, but not least, PPRC might be considered when moving the data from any ESS model to
the new storage server DS8000. Because PPRC is a host server independent approach,
similar considerations apply as outlined under “Hardware- or microcode-based migration” on
page 302.
z/OS Global Mirror under a z/OS image also allows you to move z/VM full mini disks between
different storage servers and would allow you to connect to the source disk server through
ESCON and to the target disk storage server with FICON.
In VSE/ESA data migration you might consider the following approaches:
Physical volume copy from all ESS models to the new DS8000 disk storage server
through PPRC as outlined under “Hardware- or microcode-based migration” on page 302.
Logical copy operations under VSE/ESA which allow data movement from source storage
servers to new DS8000 disk storage servers are the following:
– VSE FASTCOPY to move data between volumes with the same device geometry.
– VSE DITTO to copy individual files which allow a device migration.
– VSE IDCAMS commands REPRO or EXPORT/IMPORT to move VSAM files between
any device types.
There are other software vendor products as well which provide the capability to migrate data
onto new storage servers, for example, CA Favor.
14.6 Summary of data migration
The route which an installation takes to migrate data to one or more DS8000 series storage
servers depends on requirements for service levels, whether application down time is
acceptable, available tools and cost estimates with certain budget limits.
When coming from an ESS 750 or ESS 800, Metro Mirror seems to be the natural choice, and
allows for concurrent data migration with almost no application impact. There would be no