If an error occurs in your LTO tape, you can attempt a recovery to try and save the data on the tape. Click Recover to open another window with the recovery options. 

When the recovery window appears the first option, Run Check will determine if recovery is needed. In some cases this option will fix the issue and no further actions will be needed.

If recovery is needed there are three Recovery Methods available, the first is titled Full Recovery. This option will attempt to recover your missing data from the tape by gathering any written data that has not yet been synced and adding it into the index.

The second option, Partial Recovery will try to rectify the tape's issues by discarding any changes to the data block that the tape's index does not have information about. This may result in data that was written since the last tape index sync being lost. 

The final recovery method, titled Rollback, allows the user to select a previous generation of LTFS. The tape will then revert back to the previous generation.

CAUTION: Rolling back to a prior generation will result in the loss of data for all generations which came after the rollback generation.

Before a rollback can occur, the previous generations need to be determined. These can be found by selecting the button marked Gather Generations. Once the button is pressed the index generations will begin to populate the view.  After the index you would like to rollback to has been generated, you can select the button marked Stop.

After finding the desired generation, select it, and then click Perform Recovery.

TIP: This option should be considered a last resort. It is recommended that you select the most recent generation when rolling back to minimize the amount of data lost.