HP StorageWorks XP Remote Web Console Software - Manual (Page 35)

Chapter 2 About Universal Replicator Operations 2-13
Hitachi Universal Replicator for IBM /OS User’s Guide
Deleting journal volumes:
You can delete journal volumes under any of the following conditions:
– When the journal group does not contain data volumes (i.e., before you
create a data volume pair for the first time in the journal group, or after
all data volume pairs are released)
– When all data volume pairs in the journal group are suspended.
You can use Storage Navigator computers to delete journal volumes.
Caution:
– If you delete a mainframe journal volume from a journal group where a
data volume pair has ever been registered, the deleted volume (LDEV)
will be blocked. If you want to reuse the volume as a data volume, you
must format the volume by using Virtual LVI/LUN (VLL). Unless you
format the volume, data in the volume will not be guaranteed.
For instructions on formatting volumes, please refer to the Virtual LVI/LUN
and Volume Shredder User's Guide. Note that you do not need to format
the volume if you want to register the deleted volume as a journal volume
again.
Access from hosts to journal volumes:
If a path is defined from a host to a volume, you cannot register the
volume as a journal volume.
You cannot define paths from hosts to journal volumes. This means that
hosts cannot read from and write to journal volumes.
Journal Volume Areas
The journal volume consists of the metadata area and the journal data area.
The ratio of metadata area to journal data area is common in the journal
volumes within the journal group.
In the metadata area, the metadata that manages the journal data is stored.
For further information on the metadata area, see Table 2-3. The journal data
that the metadata manages is stored in the journal data area.
Note: If the metadata or the journal data cannot be stored for a given length of
time because the metadata or journal data areas have become full with the
metadata or the journal data that had not been discarded, the pair is
suspended according to a failure. Users can use a Storage Navigator computer
to specify this timeout period (Data overflow watch) as a journal group option.
This timeout period must be within the range of 0 to 600 seconds. For details
on journal group options, see section Changing Options for a Journal Group.
Journal Group