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Wednesday, 2 August 2017

Drive cleaning

You must clean each drive periodically or when necessary to remove the oxides that accumulate on the read-write heads. The drive cleaning ... thumbnail 1 summary
You must clean each drive periodically or when necessary to remove the oxides that accumulate on the read-write heads. The drive cleaning operation includes the task of mounting the cleaning media into the drive, cleaning the read-write head and unmounting the cleaning media. (The cleaning media will be unmounted after the amount of time specified in the Cleaning Duration option available in the Drive Cleaning Threshold Parameters tab of Hardware Maintenance Thresholds dialog box.)
Drive cleaning operation must be performed in the following situations:
  • When a drive reports that it requires cleaning.
  • When the drive cleaning threshold parameters established in the Drive Cleaning Threshold Parameters for the drive are exceeded.In both these situations, the drive can be automatically cleaned by the MediaAgent, if the Enable Auto-Cleaning options are enabled in the library.
    If the Enable Auto-Cleaning options are not enabled in the library, the drive will be marked Offline with the appropriate Offline Reason. (This information can be viewed from the Status tab of the Drive Properties dialog box.)
The MediaAgent offers several options to both monitor and perform the drive cleaning operation. This includes the following:
  • Facility to establish drive cleaning thresholds and cleaning duration. For a detailed description of this feature, see Drive Cleaning Threshold Parameters.
  • The Enable Auto-Cleaning options, which will automatically clean the drive when the hardware (drive) indicates that it requires cleaning or if the drive cleaning threshold parameters are exceeded. For a detailed description of this feature, see Enable Automatic Drive Cleaning.
  • The Clean Drive option, which when initiated, will mount the cleaning media and clean the drive. For a detailed description of this feature, see Manually Initiating a Drive Cleaning Operation using the CommCell Console.
  • Manually clean the drive, without using any of the options available in the CommCell Console. In this case you must mark the drive as cleaned from the CommCell Console after the drive cleaning operation completes successfully. For more information, see Resetting Counters When Drives are Cleaned using Library Options.
    Some libraries and drives do not support the drive cleaning feature. Refer to the manufacturer's documentation for information on whether the library supports the cleaning feature.
  • Schedule the drive cleaning operation so that the drives are cleaned regularly at fixed intervals. See Scheduling Drive Cleaning Operations for more information.
In addition, the system provides the facility to automatically identify the barcodes associated with cleaning media. See Automatically Identify the Cleaning Media using Barcodes.
The Commvault Media & Library Manager service on the CommServe checks for drives (in the CommCell) that require cleaning, every 20 minutes. You can modify the frequency by changing the Automatic Drive Cleaning check interval in Minutes default value in the Media Management Configuration (Service Configuration) dialog box.

Enable Automatic Drive Cleaning

The MediaAgent automatically mounts the cleaning tape and cleans the drive if the Enable Auto-Cleaning options are enabled for the library These options are not enabled by default.
If you enable this option, verify and ensure that you have a good cleaning media in the Cleaning Media pool. (For information on the Cleaning Media pool, see Cleaning Media.)
When a drive is successfully cleaned, a message is displayed in the Event Viewer, and the drive cleaning parameters in the Odometers tab of Drive Properties are reset.
Keep in mind that if these options are not enabled, the system does not automatically clean the drive when the hardware indicates that the drive requires cleaning. Hence subsequent mount operations in the drive may fail.
This option is not available for stand-alone drives.
Some drives do not support the drive cleaning feature. Do not enable the Enable Auto-Cleaning option for such drives.
The Enable Auto-Cleaning options can be established from the General tab of the Library Properties dialog box. The following options can be established:
  • On sense codeWhenever the hardware indicates that a drive requires cleaning, the MediaAgent will automatically mount the cleaning media and clean the drive if you enable the On Sense Code option.
    By default the On Sense Code option is disabled for a library. .
  • When thresholds exceedWhen a drive exceeds the threshold values established for the drive type in the Drive Cleaning tab of Hardware Maintenance Thresholds dialog box, the system will automatically mount the cleaning media and clean the drive if you enable the When Thresholds Exceed option.
    By default the When Thresholds Exceed option is disabled for a library.
  • Wait n day(s) after last cleaningIf you do not want to frequently clean the drives, you can specify the number of days that the MediaAgent must wait after performing an automatic drive cleaning operation, by enabling the Wait n day(s) after last cleaning option and specifying the number of days.
    By default this option gets enabled when you select the On sense code or When thresholds exceed options. The default number of days to wait is set to 3.
  • Continue using drive even if it needs cleaning during restoreIf you would like to use a drive even if it requires to be cleaned (Indicated as requires cleaning by either the On sense code or When thresholds exceed options) enable the Continue using drive even if it needs cleaning during restore option.
    This option is not enabled by default.
By default, the MediaAgent checks for drives that require cleaning every 15 minutes. You can modify this value using the Automatic Drive Cleaning check interval in Minutes option from the Media Management Configuration (Service Configuration) dialog box available in the Control Panel.

Scheduling Drive Cleaning Operations

Drive cleaning operation can be scheduled to ensure that the drives are cleaned regularly at periodic intervals. Schedules can be created for multiple drives from the library level in the CommCell Browser. In addition, schedules can also be created for the individual drives at the drive level. When the schedule is executed the job will be displayed in the Event Viewer. After the successful completion of the cleaning operation, the system resets the counters that are linked to drive cleaning. You can view these counters from the Drive Properties (Odometers) tab.
The scheduled drive cleaning operation is not available for stand-alone drives.

Manually Initiating a Drive Cleaning Operation Using the CommCell Console

Use the Clean Drive option available in the CommCell Console for each drive, to manually initiate a drive cleaning operation. When initiated, the Clean Drive operation, mounts the cleaning tape and cleans the drive. in addition, this operation also resets the counters that keep track of the number of drive events that have occurred since the drive was cleaned. (These counters can be viewed in the Odometers tab of Drive Properties.) The drive cleaning operation can also be scheduled if necessary.
Check the following before starting the drive cleaning operation:
  • Ensure that you have imported or moved cleaning media into the Cleaning Media Pool. For more information on importing cleaning media, see Import Cleaning Media.
  • If a job is in progress in the drive you wish to clean, the drive cleaning operation would fail. Ensure that the drive is free, before you start the operation.
  • In order to perform the Clean Drive operation from the CommCell Console, the library’s auto-cleaning feature must be disabled from the library’s front panel menu.Refer to the library manufacturer’s documentation for information on disabling the library’s auto-clean option from the library’s front panel.
The drive cleaning operation is not available for stand-alone drives.

Resetting Counters When Drives are Cleaned Using Library Options

Some libraries provide menu options in the library front panel to clean drives. If you use these options, you must indicate to the MediaAgent that the drive has been cleaned.
This can be done by using the Mark Drive Cleaned option in the CommCell Console. This will reset the following counters that keep track of the number of drive events that have occurred since the drive was cleaned:
  • Number of hours used after last clean
  • Number of soft errors after last clean
  • Number of hard errors after last clean
These counters can be viewed in the Odometers tab of Drive Properties.
Whenever you clean stand-alone drives, use this option from the CommCell Console to indicate that the drive has been cleaned.

Automatically Identify Cleaning Media Using Barcodes

Most cleaning media have a standard barcode pattern. This feature can be used to automatically identify the cleaning media in the library and move them to the cleaning media pool. This is done as follows:
  1. Enable the automatic media discovery option in the Media Usage tab of the Library Properties dialog box.
  2. Define all the barcode patterns that may be used in all libraries in the CommCell from the Barcode Patterns tab of the Media Management dialog box.
  3. Associate the barcode patterns for cleaning media used in the library, from the BarCode Patterns tab of the Cleaning Media Group Properties dialog box.