STORE and TurboSTORE/iX Products Manual (B5151-90003)

Chapter 3 49
Preparing Storage Devices
Preparing Tape and DDS Devices
Use the FILE command to give each device a filename that reminds you of its position.
Then use the STORESET parameter in a STORE command to reference the multiple devices.
For example, to store files to three sequential devices, use the following set of commands:
:FILE SEQ1;DEV=7
:FILE SEQ2;DEV=8
:FILE SEQ3;DEV=9
:STORE @.@.@;;STORESET=(*SEQ1,*SEQ2,*SEQ3)
The above STORE command copies all system and user files to three sequential devices. The
parentheses surrounding backreferenced filenames group the devices into a device pool.
NOTE You do not backreference the filename of a backup device immediately after
the name(s) of the file(s) you are storing when you use the STORESET
parameter. Instead, you must use a placeholder for the missing parameter
normally supplied when using a single backup device. The placeholder is
provided by the use of ";;" in the STORE command.
If you gave the backup devices a single filename such as:
:FILE T;DEV=TAPE
enter the following STORE command to copy files to a set of three sequential backup
devices:
:STORE @.@.@;;STORESET=(*T,*T,*T)
NOTE Only unlabeled media can be used for a sequential device backup. A
maximum of 8 devices can be specified in each serial device pool.
Using Tape Devices in Parallel
With parallel devices, you have the capability of reducing backup time by storing different
files on different devices at the same time. When you store files to a set of parallel devices,
the files are grouped before the store begins and then copied to multiple devices
simultaneously. For example, when you have three parallel devices, your files are
partitioned into three subsets. Files in the first subset are copied to the first backup drive,
the files in the second subset are copied to the second backup drive, and so on.
When a piece of media is filled, you are prompted to mount the next piece of media on that
device.
Depending upon the characteristics of your files and your backup devices, storing files to
parallel devices usually saves more time than using sequential devices.
Figure 3-9. illustrates a parallel device backup.