Back up each Canister whose retention days you are changing.

When data has aged beyond the maximum number days, the Canister trimming process (CanTrim) removes the data from the local drive. Unless the data has been archived or backed up to another location, it is permanently removed from access.

CanTrim deletes both the LSSN*.dat files and LSSN*.idx files. It also sends a message to the Session Indexer to delete the corresponding dtSearch indexes. When you use CanTrim to remove sessions from the Long Term Archive, the deleted session statistics are still displayed in the Portal charts and report summaries.

The length of data retention should be configured in conjunction with a backup. For example, if you want to back up every day, set CanTrim to delete session files every other day. If you run a backup before CanTrim runs, deselect the Delete session data only after backup setting so CanTrim can remove sessions. If you leave this value selected without running a backup, CanTrim never deletes any sessions, and the Long Term Canister continues to grow in size.

If this option is selected, when CanTrim is executed, you might see the following errors in the log:

03/25/12 00:40:58|DeleteLSSNDataFile: Skip trimming data file
CANISTER.dbs\LSSN_<date>_<servername>.dat, archive bit is set

These errors indicate that sessions could not be trimmed because they had not yet been archived. Configure your backup job to occur before the CanTrim operation is scheduled to run.

You can use the CanTrim settings to specify how long to retain data and whether to delete data only after a backup. For example, if you have specified seven days for CanTrim, it retains seven days worth of session data and deletes session data that is older than seven days.

1. Log in to Tealeaf as an administrator.
2. In the Portal menu, navigate to TMS.
3. Click the WorldView tab.
4. Select View > Servers.

   Complete the following steps for each of your servers for which you want to change the data retention.

5. Click the server hosting one of your Canisters.
6. Click the Canister Server node.
7. Click Canister Server configuration.
8. Click View/Edit.
9. Expand the default node.
10. Look at value for LOCAL_DIRECTORY.
    Check the space available on this volume. Before you change the days to retain, you should verify that you have sufficient space to retain the data.

    Note: Typically, this volume is the same as where the Canister is located, but you should verify.
11. If sufficient space is available, you can change the value for Number of Days to Retain Data. This value defines the number of days that session data is retained in the Canister. When data is aged longer than this value, data trimming operations in the Canister remove it permanently.
    1. Click the Canister node, which is a different node in Server view.
    2. Click Canister configuration.
    3. Click View/Edit. The Canister configuration dialog opens.
    4. Click the Canister Services tab.
    5. Change the Number of Days to Retain Data setting.

       If you increase the number of days of retention, try increasing a small amount first to see the impact on available space in your volume.

       Note: If you decrease the number of days of retention, the next CanTrim operation removes data that is now identified to be older than the newly designated number of days to retain. Never set this value below 2 days.
12. Click Save.
13. Submit the task and run the job immediately.