Chapter 2 – Concepts
28
Example 6
This example illustrates the importance of File Group order.
In this example, files ending in .txt in folder project01\ are allocated to the same File
Group as the other files in this folder. If the order of the first two rules was changed,
files ending in .txt would be allocated to the same File Group as the.txt files in the
other folders.
Tapes: Volumes, Volume Sets, and Automatic
Replication
The nTier File Migrator software can automatically create multiple tape cartridge
replicas. For this software, the term “Volume” refers a complete set of replica tapes
which, when up-to-date, all contain the same data. If replication is not enabled a
Volume refers to an individual tape cartridge.
A Volume Set stores files from designated File Groups and consists of one or more
Volumes. As more data is written to a Volume Set, the initial Volume eventually
becomes full. At a preset threshold, defined by the administrator, the system
automatically adds another Volume by taking the appropriate number of tapes from the
blank media set and extends the Volume Set.
The data on replicated tapes in a Volume Set are kept synchronized whenever the tapes
are available to the system. If one or more tapes in a Volume Set are removed from the
library, the system maintains a record of which files need to be written to those tapes.
When tapes are reintroduced into the library, the data on them is automatically brought
up to date.
With the exception of the blank media set and quarantined media set, all media within
a Volume Set must be either WORM tape or rewritable. Tape replicas must all be of the
same capacity.
One unique Volume Set, termed the blank media set, contains all the tapes that are
recognized by the system but are not formatted for storing data. These may be new
(unused) tapes or rewritable tapes that have been reformatted by the system
administrator.
File Group
File name or path pattern
Exclude pattern
File Group 1
\project01\*
File Group 2
*.txt
File Group 3
*
