Quantum Marine Sanitation System 3.5.2 User Manual

Chapter 11  Data Migration Management

Policy Classes and Relationships

StorNext User’s Guide

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Policy Classes and Relationships

A policy class defines how files will be managed in a directory and 

subdirectories. These are the available policy class settings:

• Number of copies to create
• Media type to use when storing data
• Amount of time to store data after data is modified
• If disk-to-disk relocation is enabled, the amount of time (in days) 

before relocating a file

• Amount of time before truncating a file after a file is modified 

Policy classes can be related to one or more directories. In this situation, 

all files in that directory and sub-directories are governed by the policy 

class. The connection between a policy class and a directory is called the 

relation point.
Here are some examples of policy class usage:

• A directory in which to store backups every night is created. This 

directory is seldom accessed after the files are copied over. A policy 

class could be set up to create two tape copies of the files, store one 

copy of the files to AIT media after residing on disk for 10 minutes, 

and then truncate the other set of files immediately after storing the 

other set to tape in order to free up disk space. This policy can be 

associated with a directory such as: /sandsm/dsm1/backup.

• A directory has been created to store all documents that are accessed 

frequently, and if truncated, need to be retrieved quickly. The policy 

class in this case could be set up to create a single tape copy, store the 

files to LTO media 15 minutes after being on disk, and then truncate 

after 60 days of non-use. This policy can be associated with a 

directory such as: /sandsm/dsm1/docs.

11

StorNext includes a licensable Stub File feature. When this feature is 

enabled, third-party applications can gather information about a file by 

reading a portion of the file (called a stub) rather than reading the entire 

file. When you create a policy class you can enable stub file support and 

specify the size of the stub file (in kilobytes). When stub file support is 

enabled, the beginning portion of the file (up to the size you specified)