Readability check is used to check the backup data readability. During the check the data on tape media is read in blocks, and the structure of tape is checked and recorded. It also checks whether all determined backup sets on the tape are recorded in the database and vice versa.
To perform a readability check, you have to set it up on the following levels:
- Set up a readability check on the media pool level.
- Configure a readability check by a special media event.
- You can also start a readability check immediately.
The readability check can only be applied if a medium EOL has not expired; it is not applicable for EOL-free media. For details, see Tape media EOL.
Setting up readability check on the media pool level
You can specify the readability check settings when configuring a media pool or later in the media pool properties.
- From Main Selection -> Media Pools, click New Media Pool or double-click an existing media pool. The New Media Pool window or properties of the media pool opens. If you are creating a new media pool, specify the required fields, as explained in Configuring a Media Pool.
- Switch to the Readability Check tab and specify the following values:
- Readability check limit [days]: You have to specify the frequency – number of days > 0 – when the readability check will run. For example, 90 means that it will run every 90 days. Specifying 1 will activate daily readability check. Note that readability check can only be applied if a medium EOL has not expired and is not applicable for EOL-free media. For details, see Managing EOL.
- Expiration of read check overdue [days]: Specify the number of days when a readability check will be overdue. This calculation is based on the readability check limit [days] and the value of expiration overdue. The status of the readability check is shown in the media table.
- Repeat rate for readability check [times]: If you select Unlimited, the tape is checked according to the specified frequency. If you define Execute, the check is repeated as many times as specified.
Configuring readability check by a special media event
If you want to perform a readability check, you have to set up a schedule (or use existing schedule) to be able to link a media event to it. For details, see Creating a Schedule.
- In the Main Selection -> Scheduling -> Schedules, select the schedule to which you want to link the event, select New and then New Media Event. A new media event is opened in which the tab Parameter is selected.
- Optionally, under the Sequence control, set up the Priority of your media event. SEPuler always executes the schedules with higher priority first. Default priority level is 1, which is the lowest priority (the highest is 99). The only exception are the schedules with priority 0, which override all other priorities and are always executed. For details, see Setting Event Priorities. You can also enable the Blocking date. This option should be used together with high priority for special events. If checked, the blocking event will block events of the same type of a lower priority, ensuring the readability check to be processed in case other readability checks are scheduled at the same time. For details, see Blocking Events.
- Under the Media action, select Readability check.
- Under the Parameter, specify the following options:
- Media Pool: Select a media pool for which you want to run a readability check, e.g., BCK_LTO_Archive.
- Drive: Optionally, select a drive which will be used for the check.
- Media: Optionally, select a specific tape media for the check. If no medium is selected, the action applies to all media in the selected media pool.
You can view the status of your readability check by selecting Job State -> Media Actions. Check the columns State and Action to verify the status of your readability check. For more details, double-click the relevant media action to open its properties. Under the Main Log tab the following information about performed readability check is displayed:
- Start and stop time of the readability check.
- On which device the medium was checked.
- The SEP sesam label of the medium.
- The last time the medium was initialized.
- The read throughput every minute.
- Information about the stored savesets on the medium.
- All segment marks of the tape.
- Readability check status (at the end of the log, e.g., success, error).
|As of 4.4.3 Beefalo V2, you can check the status and other details of your media actions online by using new Web UI. For details, see SEP sesam Web UI.|
Starting a readability check immediately
You can also start your readability check immediately under Activities -> Immediate Start -> Media Action, where you have to specify the media pool for which you want to run a readability check. Optionally, a specific medium can also be selected directly.