Chapter 3. Operating NetView FTP V2.2.1 MVS - IBM

Chapter 5. Setting Up and Maintaining the Checkpoint Data
Set
This chapter describes how to set up and maintain the checkpoint data set for
SNA-type transfers. The checkpoint data facility does not apply for OSI-type transfers.
During a file transfer the receiving server periodically writes a checkpoint record
into the checkpoint data set. The checkpoint record contains all the information
that NetView FTP V2.2.1 MVS needs to restart the file transfer. If a file transfer is
interrupted NetView FTP can use this information to restart the file transfer from the
last checkpoint rather than from the beginning of the file.
All servers at one NetView FTP V2.2.1 MVS installation can share the same checkpoint
data set. This allows a server other than the one that began a file transfer to
restart an interrupted file transfer. You can also define a checkpoint data set for
each server in your installation. If you do this, however, an interrupted file transfer
can only be restarted by the same server. The request originator must ensure this
by specifying that the request can be processed only by a specific server. How to
do this is described in the NetView FTP Parameter Reference.
Setting Up the Checkpoint Data Set
Setting up the checkpoint data set involves doing the following:
� Deleting the old checkpoint data set if necessary
� Defining a new checkpoint data set
� Initializing the checkpoint data set.
Member DVGMXCR1 in library DVG.NFTP230.INSTLIB on the NetView FTP V2.2.1
MVS distribution tape contains a batch job that deletes the old checkpoint data set
and defines and initializes a new checkpoint data set. The batch job uses the utility
IEBDG to create a sequential file containing initial values for the checkpoint data
set and uses AMS to load the sequential file into the checkpoint data set.
This batch job is shown in Figure 42.
Member DVGMCXRD in library DVG.NFTP230.INSTLIB on the NetView FTP
V2.2.1 MVS distribution tape contains the IDCAMS parameters for the job
DVGMXCR1. Member DVGMCXRD is shown in Figure 43 on page 75.
Note: The values in bold are generated by the installation generator. You can
modify them to suit your system. You must insert values for all lowercase variables.
All other parameters must be specified as shown in the sample.
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