Volume Sets and Volumes for ON-Archive
Volume Sets and Volumes for ON-Archive
Definition
ON-Archive
for the Informix database organizes the physical media that it uses to store backup data (that is, archived data and backed up logical-log files) into volume sets and volumes. Volumes are organized into volume sets, which are defined by characteristics such as type (that is, disk or tape), logical device, density, and so on. ON-Archive manages the volumes in a volume set, so allowing backup data to span multiple volumes without problem.Use
The number of volumes you require in a volume set depends on how large your database is and your archive and backup approach – that is, how often you perform archives and backups. This is shown in the example below.
If you wanted to archive at level-0 (full) daily during the working week with two tape volumes per archive and a four week (28 day) cycle (the tapes are reused after this period), you would require 40 volumes (two tapes per day x five days per week x four weeks).
If you wanted to back up your logical logs daily during the working week with a single tape volume per backup and a four week (28 day) cycle (the tapes are reused after this period), you would require 20 volumes (one tape per day x five days per week x four weeks).
Make sure of the following when you perform an archive or backup with
ON-Archive :Integration
Every archive and backup request in
ON-Archive requires a volume set. The volume set points to the logical device to be used for the archive or backup. The logical device in turn points to the physical device (or to a list of available physical devices). Therefore, a volume set provides a logical grouping for your archives and backups and associates these with a specific logical device.To see how volume sets and volumes fit into the wider picture of configuring
ON-Archive for data recovery, see Configuration of ON-Archive.
See also:
Informix documentation
at http://www.informix.com