Using NS3000/iX Network Services (36920-90008)

Chapter 5 91

Network File Transfer

Using Checkpoint and Restart with DSCOPY

intermediate failure occurs, the ﬁles will not be purged. Therefore,

transfers that fail and are not restarted to a successful completion will

leave restart ﬁles unpurged; NFT will not purge unused restart ﬁles.

Similarly, for generic transfers a permanent ﬁle called GENSETx, where

x is a number from 0 to 9, is created to hold the list of ﬁles to be

transferred on the producer node. This ﬁle is purged when the generic

transfer is complete. Likewise, a ﬁle called NFTSCRxx, where xx is a

number from 0 to 99, is created on the consumer node when the REP

option is speciﬁed. This ﬁle is used as a scratch ﬁle to hold the target

ﬁle during the transfer. When the transfer is complete, the old target

ﬁle is purged and the scratch ﬁle is renamed to the target ﬁle name.

Again, if an intermediate failure occurs, these ﬁles will not be purged. If

the transfer is not restarted to a successful completion, these ﬁles will

remain unpurged; NFT will not purge unused generic or scratch ﬁles.

Using the DSCOPYI File for Checkpointing

Transfers initiated using the DSCOPYI command ﬁle can also use

CHECKPT/RESTART. If a failure occurs during any of the transfers in

the list, that transfer can be restarted in the normal way. When that

transfer is complete, the next transfer in the list will take place as if no

failure had ever occurred. When checkpointing from a DSCOPYI ﬁle

note the following conditions. First, a separate restart ID will be

returned for each transfer. Second, in order to restart a transfer from

DSCOPYI, the same ﬁle equation that was speciﬁed for checkpointing

must be in effect when the restart is attempted.

NOTE The RESTART keyword cannot be used from within a DSCOPYI ﬁle.

Using CHECKPT and RESTART in Shared

Environments

Checkpointing is allowed when the producer or consumer environments

were created using REMOTE HELLO. If a restart is necessary, however,

NFT will always attempt a programmatic logon to the producer or

consumer nodes. In other words, NFT will set up its own, temporary

environment, equivalent to your using the square brackets to specify

the remote logon. If a password is needed to access one or both of these

environments, it will not be available to NFT, and the restart will fail.

The only way to ensure that this problem will not occur is to use the

programmatic logon feature of NFT when CHECKPT is speciﬁed. The

password(s) will then be available to NFT, so that a subsequent restart

will be able to logon to the remote node(s).

Files Not Allowed with CHECKPT and RESTART

CHECKPT/RESTART is not allowed with message or circular ﬁles. It is

also not allowed with ﬁles of variable length records in interchange

mode.