You may want to make copies of individual volumes under the following
conditions:
- Message ARC0421I, written to the console when a tape volume is
marked full, allows making an alternate copy of that volume automatically,
if you are not using the duplex tape option to create alternate tapes.
- You have replaced an original volume with an alternate volume.
You would then immediately want to make a new alternate volume for
protection against loss of what is now the only usable volume.
- An alternate volume is lost so that you must make a new alternate
volume, even though it appears (in a TTOC record) that an alternate
volume already exists.
When DFSMShsm makes an alternate volume, it records the alternate
volume in the OCDS, thus associating the alternate volume with the
original volume. For copying individual volumes, if an alternate volume
already exists:
- DFSMShsm replaces the old alternate volume with the new alternate
volume.
- DFSMShsm issues message ARC0436I.
- No record is kept of the old alternate volume.
- For duplex tapes only, the tape volume exit ARCTVEXT is invoked,
if active, to release the previous alternate tape volume through the
tape management system. A flag in the ARCTVEXT parameter list indicates
that the tape being released is an alternate tape being replaced by
a user TAPECOPY, and that the original tape is not being released.
- If SETSYS PARTIALTAPE(MARKFULL) is specified, the original volume
is marked full.
The command to make alternate volumes for individual volumes is:
TAPECOPY ORIGINALVOLUMES(ovol1,ovol2,...,ovoln)
TAPECOPY ORIGINALVOLUMES(ovol1,ovol2,...,ovoln) -
ALTERNATEVOLUMES(avol1,avol2,...,avoln)
This command copies the volumes specified, creating an alternate
tape volume for each. If you use the first form of the command, a
default volume serial number of PRIVAT is used for the alternate tape
volumes. PRIVAT indicates to DFSMShsm that a scratch volume be mounted
for each alternate tape volume. However, if you use the second form
of the command, DFSMShsm uses the volumes you specify with the ALTERNATEVOLUMES
parameter to become the alternate volumes. If you use the ALTERNATEVOLUMES
parameter, you must specify exactly the same number of volumes with
the ALTERNATEVOLUMES parameter as you specified with the ORIGINALVOLUMES
parameter. There is a one-to-one correspondence between the original
volumes and alternate volumes that you specify. That is, ovol1 is copied to avol1, ovol2 is copied to avol2,
and so forth.
An alternative exists for copying your existing DFSMShsm-owned
volumes. You can issue a LIST command to obtain a list of your ML2
and backup volumes. You can then issue a LIST TTOC command to determine
which of the volumes have alternate copies already. Send the LIST
TTOC command output to a data set. Edit
the data set to remove those volumes for which you do not want to
make an alternate copy, convert the data set to the format required
for the input data set, and issue the following command:
TAPECOPY INDATASET(volcopy.list.dsname)
DFSMShsm makes an alternate copy of each of the volumes contained
in the list of volumes provided by the data set.