My site is currently running ADSM Version 1 under AIX. We are using the
EXPORT NODE command with the FILEDATA option to produce offsite backup
tapes for disaster recovery. We are preparing for a disaster recovery
test. Since the EXPORT currently takes almost 24 hours and the whole
test period is only 24 hours, the performance of the corresponding IMPORT
operation is a matter of some concern.

How does the running time for an IMPORT from tapes with file data
compare with the running time for the corresponding EXPORT?

The documentation for the IMPORT command indicates that it is possible
to import a subset of the data on a tape produced by EXPORT NODE,
selecting by node, filespace, or both. Is this in fact true? If so,
how does the performance of a selective IMPORT compare with that of
a full IMPORT? For example, does importing half of the data take 50%
of the elapsed time of the full import, or almost the same time, or
something in between?

Are the files on an EXPORT tape grouped by node? For example, would
the command

  export node alpha.umis.upenn.edu,beta.umis.upenn.edu filedata=allactive

produce a tape with all the active files from alpha followed by all the
active files from beta? Similarly, will the files from a given filespace
be grouped together on an EXPORT tape?

Once an IMPORT command places some files in the storage pools on the
disaster recovery server, will it be possible for the clients owning
those files to begin restoring them while the IMPORT command is still
running?