If you are dumping to or loading from local devices (that is, if you are not performing backups over a network to a remote Backup Server), you can specify dump devices either by providing their physical locations or by specifying their logical device names. In the latter case, you may want to create logical dump device names in the sysdevices system table of the master database.
If
you are dumping to or loading from a remote Backup Server, you must
specify the absolute path name of the dump device. You cannot use a
logical device name.
The sysdevices table stores information about each database and backup device, including its physical_name (the actual operating system device or file name) and its device_name (or logical name, known only within Adaptive Server). On most platforms, Adaptive Server has one or two aliases for tape devices installed in sysdevices. The physical names for these devices are common disk drive names for the platform; the logical names are tapedump1 and tapedump2.
When you create backup scripts and threshold procedures, use logical names, rather than physical device names, and whenever possible, you must modify scripts and procedures that refer to actual device names each time you replace a backup device. If you use logical device names, you can simply drop the sysdevices entry for the failed device and create a new entry that associates the logical name with a different physical device.
Make sure that the device driver options you include
with the dump command are accurate. Backup Server does not verify
any device driver options you include during a dump command. For
example, if you include a option that forces Backup Server to rewind
a tape before use, it will always rewind the tape to the beginning
instead of reading the tape from the point of the dump
