StorNext: Truncation is not working

StorNext: Truncation is not working

 

Files Are Not Truncated as Expected


Even if the truncation mintime requirement is met, files may not be truncated. Files are truncated only to keep the file system below the low-water mark (by default 75% of the capacity). When the daily truncation policies run, the oldest files are truncated first in an effort to bring the file system usage below the low-water mark. Thus, files may remain on disk even though their truncation mintime requirement has been met if the disk space is not required.


You can use the StorNext GUI to adjust the low-water and high-water marks on each file system if more free disk space is desired. A temporary option to free up disk space is to run the following command:

fspolicy -t -c <policyclass> -o <goal>

The goal argument is a disk usage percentage. For example specifying "-o 65" will truncate files until the disk usage either reaches 65% or there are no more valid truncation candidates, i.e. the mintime requirement has been satisfied.

"Old" Files Not Truncating According to Policy Class

Truncation uses the file access time to determine if the truncation mintime requirement has been satisfied. If any application changes the access time of a file, the aging of the file restarts


An example of this is where image files are listed using the thumbnail mode on an Apple Macintosh. This causes the OS to read the file to present this thumbnail, and the access time of the file gets updated to the current time. This in turn results in StorNext determining this file has not satisfied the truncation mintime requirement.


Emergency truncation ignores mintime so the files could still be truncating if the file system fills up. However, the best solution is to modify the way files are accessed so as to not update the access time. In the above example, this would mean not using the thumbnail view.

Small Files Not Truncating


If a policy class has been configured to use stub files, files with a size that is less than or equal to the stub size will not get truncated.

One or More of the Files Have Not Been Stored

Truncation will not take place unless ALL of the copies specified in the policy have been successfully stored.

Audience: 
Public Unrestricted
Review/Evaluate: 
2013-06-15
Document Type: