DFSMShsm invokes dynamic allocation (SVC 99) to allocate the data
sets in the ALLOCATE list:
During ARECOVER processing, dynamic allocation allocates the data
set as sequential extended format or not sequential extended format
(regardless of the number of stripes at the backup site) according
to what was specified at the recovery site for the DATA SET NAME TYPE
attribute in the data class.
Dynamic allocation also allocates the data set as single-stripe
or multiple-stripe sequential extended format (regardless of the number
of stripes at the backup site) according to what was specified at
the recovery site for the SUSTAINED DATA RATE attribute in the storage
class. If GUARANTEED SPACE = YES is specified, the number of volsers
or VOLCNTs specified is the number of stripes; the value for SUSTAINED
DATA RATE is ignored.
Dynamic allocation allocates the data set as a data set that is
not sequential extended format if the attribute DATA SET NAME TYPE
in the data class is defined as (EXTENDED,C), and one of the following
conditions is met:
SMS is not active at the recovery site.
None of the SMS-managed volumes is defined.
None of the SMS-managed volumes is connected to an ESCON® 3990 model 3.
None of required volumes are available.
Dynamic allocation does not allocate a
data set if the attribute DATA SET NAME TYPE in the data class is
specified as (EXTENDED,R), and one of the following conditions is
met:
SMS is not active at the recovery site.
None of the SMS-managed volumes is defined.
None of the SMS-managed volumes is connected to an ESCON 3990 model 3.
Insufficient volumes are available to meet the allocation.
Insufficient space is available on the selected volumes.
DFSMSdss performs a logical data set restore for a sequential
extended format data set as follows:
A sequential extended format data set that was multiple-stripe
when it was backed up can be restored as a multiple-stripe or single-stripe
sequential extended format data set, depending on the storage class
SUSTAINED DATA RATE value, and the availability of the required volumes.
Conversely, a sequential extended format data set that was single-stripe
when it was backed up can be restored as a multiple-stripe or single-stripe
sequential extended format data set, depending on the storage class
SUSTAINED DATA RATE value and the availability of the required volumes.
A data set that was sequential extended format when backed up
is recovered as a non sequential extended format but still SMS-managed
data set if no SMS volumes supporting sequential extended format data
sets are available.
A data set that was not sequential extended format when it was
backed up is always recovered as a data set that is not sequential
extended format. DFSMShsm will not convert a data set that is not
sequential extended format to a sequential extended format data set
through ARECOVER processing.
If the data class attribute DATA SET NAME TYPE is modified
to indicate that the data set should be allocated as a data set that
is not sequential extended format, the restore does not occur.