Magnetic Libraries - How To

If you have already configured a disk as a shared mount path, it will be reserved by one of the MediaAgents and therefore will not be available to other computers. Use the following procedure to detect the disk on a new MediaAgent, if the disk is already configured as a mount path:

Install the shared dynamic disk driver on the new MediaAgent computer if it is not already installed.
Verify and ensure that the disk is visible to the Operating system of the new MediaAgent. This can be done by opening the Computer Management window from the new MediaAgent. Make sure that the disks are visible to the operating system under the Device Manager level.
Note down the MediaAgent which has the active reservation from the shared disk properties. (See View the Status and Other Properties of a Shared Disk Device for step-by-step instructions.)
Run the following tool on the MediaAgent which needs to be added to the sharing group:
<software installation path>\Base\ScsiCmdTool.exe
From the menu, select the following options, in the appropriate prompt:
- First select the Perform a quick bus scan option.
- Then select the Select a device for testing option and then select the device.
- Next select the Preempt Persistent Reservation - One step option.
- Exit the tool.
The active reservation will be removed from the MediaAgent. (step 2)
Open the Volume Explorer and detect the volumes in the new MediaAgent. (See steps 1 to 5 of the procedure for Configure Shared Magnetic Libraries With Dynamic Mount Paths for step-by-step instructions on opening the Volume Explorer.)
Configure the device for the new MediaAgent.
Run the ScsiCmdTool.exe tool in the original MediaAgent that was determined in steps 2 and 3.
Repeat step 4 and 5 in this MediaAgent.
The active reservation will be added to the MediaAgent.

View or Modify the Device Properties for Magnetic Libraries with Static Mount Paths

To modify the device properties for magnetic libraries with static mount paths:

From the CommCell Browser, right-click a mount path for which you wish to view the modify the properties, and then click Properties.
If necessary you can:
- Change the Device Alias Name
- Enable or disable the device by selecting or clearing the Device Enabled option.
Click OK to save the changes.

View or Modify the Properties of Disk Devices in a Dynamic Mount Path

To view or modify the properties of disk devices in a dynamic mount path:

From the CommCell Browser, right-click the mount path associated with the shared disk device for which you wish to view the properties, and then click Properties.
Click the Shared Disk Device tab of the Mount Path Properties dialog box.
You can change the Device Alias Name or enable or disable the shared disk device

You can also view the status, currently reserved MediaAgent name and other information pertaining to the device.

View or Modify the Device Properties for Magnetic Libraries with Static Mount Paths

To modify the device properties for magnetic libraries with static mount paths:

From the CommCell Browser, right-click a mount path for which you wish to view the modify the properties, and then click Properties.
If necessary you can:
- Change the Device Alias Name
- Enable or disable the device by selecting or clearing the Device Enabled option.
Click OK to save the changes.

View or Modify the Properties of Disk Devices in a Shared Mount Path

To view or modify the properties of Disk Devices in a shared mount path:

From the CommCell Browser, right-click a mount path for which you wish to view the MediaAgents, and then click Properties.
Click the Device Paths tab of the Mount Path Properties dialog box.
You can change the Maximum number of writers by clicking the Edit button.

You can enable or disable the MediaAgent's access to the device by selecting or clearing the enabled button.

On mount paths associated with replicated disks, you can modify the read-write access to the mount path. This should not be done for Magnetic Libraries on Replicated Disks used for the MediaAgent Replication solution.

Deconfigure a Shared Disk Device

Before you Begin

Be certain that the mount paths using the device are deconfigured. See Deleting a Mount Path for more information.

To deconfigure a shared disk device::

Display the Library and Drive Configuration window.
Click the Shared Disk Device tab.
Right-click the disk device that you wish to deconfigure, and then click Deconfigure.
Click Yes in the Confirm Deconfigure prompt.

The device is deconfigured.

NOTES

After rebooting all the MediaAgents which shares this disk, the disk will be available for other applications.

Establish the Low Watermark for a Magnetic Library

Related Topic

Modify the low watermark

Required Capability: Capabilities and Permitted Actions

To establish the low watermark for a magnetic library:

From the CommCell Browser, right-click the magnetic library for which you wish to establish the low watermark, and then click Properties.
In the Low Watermark box, type or select the minimum percentage of free space at which the low watermark warning should be generated.
If the amount of free space, for all the combined mount paths, reaches or falls below the low watermark, the MediaAgent displays a message in the Event Viewer and sends an Alert, if configured.

Configure the Size of Magnetic Volumes

Required Capability: Capabilities and Permitted Actions

To configure the size of magnetic volumes:

From the Tools menu in the CommCell Console, click Control Panel.
Double-click Media Management Configuration.
Select Service Configuration tab.
Modify the Magnetic volume physical size high watermark in GB parameter as required.
Click OK to save the changes.

Modify the Mount and Unmount Timeouts for Magnetic Libraries

Related Topic

Configure Timeouts

Required Capability: See Capabilities and Permitted Actions

To modify the mount and unmount timeouts for magnetic libraries:

From the CommCell Browser, right-click the magnetic library for which you wish to change mount and unmount timeout periods, and then click Properties.
In the Mount and Unmount box, type or select the timeout periods.
Click OK to save the changes.

Create Read-Only Archive Files on Disk Systems

Related Topic

Configure Archive Files as read only

Required Capability: Capabilities and Permitted Actions

To create read-only archive files in a magnetic library on disk systems:

From the CommCell Browser, right-click the magnetic library for which you wish to create read-only archive files, and then click Properties.
From the General tab of Library Properties, click the Mark Archive Files as Read-Only option.
Click OK to save the changes.

NOTES

This option will only affect files that are subsequently created by data protection and auxiliary copy operations to this library. Permission to files that are already available in this library will not be affected.

Enable Single Instancing of Data on a Magnetic Library

Related Topic

Enable Support for Single Instancing of Data (Content Address Storage)

Required Capability: Capabilities and Permitted Actions

To enable single instancing of data on a magnetic library:

From the CommCell Browser, right-click the magnetic library for which you wish to establish the single instancing of data, and then click Properties.
Click the Mount Paths tab. Note that mount paths enabled with hardware single instancing must be less than 100 characters long. Otherwise hardware single instancing might not be employed successfully.
Click the Disks within this library support hardware single instancing option.
Click OK to save the information.

Enable or Disable the Magnetic Library

Required Capability: Capabilities and Permitted Actions

To enable or disable a magnetic library:

From the CommCell Browser, right-click the magnetic library that you wish to enable or disable, and then click Properties.
From the General tab of Library Properties, click the Enable Library option.
Click OK to save the changes.

View the Magnetic Library Offline Reason

To view the offline reason for a magnetic library:

From the CommCell Browser, right-click the magnetic library for which you wish to view the offline reason, and then click Properties.
Information on the magnetic library offline reason is displayed in the Offline Reason box.

Establish the Mount Path Allocation Policy for a Magnetic Library

Related Topic

Establish the Mount Path Allocation Policy for the Library

Required Capability: Capabilities and Permitted Actions

To establish the Mount Path Allocation Policy for a magnetic library:

From the CommCell Browser, right-click the magnetic library for which you wish to establish the mount path allocation policy, and then click Properties.
Click the Mount Paths tab.
Click either the Maximum Allowed Writers option or the Allocate No. of Writers option and then select the maximum number of writers.
Click OK to save the information.
From the CommCell Browser, right-click the mount path within the magnetic library and then click Properties.
Click the Allocation Policy tab.
Click either the Maximum Allowed Writers option or the Allocate No. of Writers option and then select the maximum number of writers.
Click OK to save the changes
Repeat steps 5, 6, 7 and 8 in all the mount paths associated with the magnetic library. Keep in mind that the sum of the writers allocated in the mount paths should be equal to the total mount paths allocated in the magnetic library.

Establish the Mount Path Usage for a Magnetic Library

Related Topic

Establish the Parameters for Mount Path Usage

Required Capability: Capabilities and Permitted Actions

To establish the Mount Path Usage for a magnetic library:

From the CommCell Browser, right-click the magnetic library for which you wish to establish the mount path allocation policy, and then click Properties.
Click the Mount Paths tab.
Click either the Fill and spill mount paths or the Spill and fill mount paths options.
Click OK to save the information.

Enable Managed Disk Space for Magnetic Data

Related Topics

Required Capability: See Capabilities and Permitted Actions

To enable managed disk space for magnetic data:

Right-click the storage policy copy for which you wish to enable or disable Data Aging, and then click Properties.
From the Retention tab of the Copy Properties dialog box, select the Enable Managed Disk Space for magnetic data option and click OK.
From the Mount Paths tab of the Library Properties dialog box, set the start and stop data aging disk capacity thresholds in the Start aging when data occupied on disk is n % and the Stop aging when data occupied on disk is n % boxes, and click OK to save changes.

View a List of Storage Policies Accessing the Magnetic Library

To view the list of Storage Policy accessing the magnetic library:

From the CommCell Browser, right-click the magnetic library for which you wish to view the storage policies, and then click Properties.
Click the Associations tab.
All the Storage Policies and the Storage Policy Copies accessing the magnetic library are displayed.

Migrate a Magnetic Library

Required Capability: See Capabilities and Permitted Actions

To perform a magnetic library migration from one MediaAgent to another MediaAgent:

Right-click the magnetic library that you want to migrate to another MediaAgent and click Migrate Magnetic Library.
A message is displayed indicating that this operation migrates the magnetic library to another MediaAgent. Click OK.
The Select MediaAgent dialog box is displayed. This dialog box displays the current MediaAgent that the magnetic library is associated with and allows you to select a MediaAgent to migrate to. From the drop-down list, select the MediaAgent you want to migrate to and click OK.
The magnetic library will now be associated with the selected MediaAgent. To view the magnetic library properties to verify successful migration, right click on the magnetic library where you want to view the properties, and click Properties.
The MediaAgent is displayed on the General tab.
Make sure that the mount path associated with the magnetic library, points to valid path. (See Add or Modify Mount Paths for step-by-step instructions.)

Deconfigure a Magnetic Library

Data associated with a library will be lost, when it is deconfigured.

Before you Begin

Be certain that the library that you want to remove is not in use. Use the Job Controller to find and kill any jobs that use the library.
Make sure that every storage policy copy associated with the library has been deleted. Determine the storage policies accessing the library as described in View the Storage Policies Accessing a Library.

To deconfigure a magnetic library:

Display the Library and Drive Configuration window.
Right-click the library that you want to deconfigure, and then click Deconfigure.
A prompt appears, reminding you that the library's storage policy copies must be deleted in order for the library to be deconfigured. If no storage policy copies are associated with the library and you want to deconfigure, click Yes.
The magnetic library is removed from the Library and Drive Configuration window.

Add or Modify a Mount Path

Required Capability: Capabilities and Permitted Actions

To add or modify a mount path to an existing magnetic library:

Display the Library and Drive Configuration window.
Select the library to which you want to add a mount path, right-click, and then select Add Mount Path.
In the Add Mount Path dialog box, select either Local Path or Network Path.
If you select Local Path, click Browse to select a mount path, or enter a mount path.
If you select Network Path, type the user name and password to access the network share. Click Browse to select a mount path, or enter a mount path.
Click OK. The mount path is added to the specified location.

Enable Unbuffered I/O on a Mount Path

Related Topic

Use Unbuffered I/O

Required Capability: Capabilities and Permitted Actions

To enable unbuffered I/O on a mount path:

From the CommCell Browser, right-click the mount path that you wish to enable unbuffered I/O, and then click Properties.
From the General tab of Library Properties, click the Use unbuffered I/O option.
Click OK to save the changes.

Enable or Disable a Mount Path

Required Capability: Capabilities and Permitted Actions

To enable or disable a mount path:

From the CommCell Browser, right-click the mount path that you wish to enable or disable, and then click Properties.
From the General tab of Library Properties, click the Enable MountPath option.
Click OK to save the changes.

View the Mount Path Offline Reason

To view the offline reason for a mount path:

From the CommCell Browser, right-click the mount path for which you wish to view the offline reason, and then click Properties.
Information on the mount path offline reason is displayed in the Offline Reason box.

Establish Maximum Space Allocation on a Mount Path

Related Topic

Establish Space Allocation on the Mount Path

Required Capability: Capabilities and Permitted Actions

To establish maximum space allocation on a mount path:

From the CommCell Browser, right-click the mount path that you wish to establish the space allocation, and then click Properties.
Click the Allocation Policy tab.
In the Space Allocation section, establish one or more of the following options:
- Specify the minimum reserve space in the Reserve Space box.
- Specify the maximum space that can be used by the mount path by choosing either the Use until free space on mount path reaches Reserved Space or Do not consume more than n GB options.
Click OK to save the changes.

NOTES

In some situations the mount path may consume more space and exceed the specified minimum reserve space. Consider the following example:
If you have established the minimum reserve space as 512 MB, and run a 2 streamed data protection operation when the disk space is 515 MB, both the streams will use a minimum of 25 MB before spanning to an alternate mount path. In such a situation the free space will fall below the specified 512 MB.

This could also happen if 2 concurrent single-streamed data protection operation is initiated to the same mount path, using 2 different storage policies.
Similarly, the system may consume more than the specified maximum space. Consider the following example:
When a data protection job is initiated, the system checks for the available disk space and verifies whether it is less than the specified maximum space. For example if you have specified 1 GB as the maximum space and if you have used .75 GB, the data protection job will be initiated using the mount path. However, if the size of the data is .5 GB, the system will write the entire data. In such a situation the space consumed will be more than the specified maximum space.

Note that a data protection operation will generally write to the mount path until the minimum reserve space is reached, before spanning to an alternate path.

Reduce Data Fragmentation on a Mount Path

Related Topic

Reduce Fragmentation of Data on a Mount Path

Required Capability: Capabilities and Permitted Actions

To reduce data fragmentation a mount path:

From the CommCell Browser, right-click the mount path that you wish to establish the space allocation, and then click Properties.
Click the Allocation Policy tab.
In the Fragmentation section, click and select the Minimize fragmentation by allocating write blocks of n MB option and specify the size that must be pre-allocated for each write operation in the box.
Click OK to save the changes.

Magnetic Library Maintenance

Related Topic

Magnetic Library Maintenance

Required Capability: Capabilities and Permitted Actions

To execute magnetic library maintenance on selected mount paths:

Right-click the magnetic library containing the mount paths you wish to execute magnetic library maintenance and click Magnetic Library Maintenance.
From the Magnetic Library Maintenance window, select the desired mount paths in the Analysis check box.
- Click OK to execute the maintenance job immediately.
- Click Schedule to schedule the job. From the Schedule Details tab, select the necessary scheduling option. Click OK to save the schedule.

View the Contents of a Mount Path

Required Capability: Capabilities and Permitted Actions

To view the contents of a mount path

From the CommCell Browser, right-click the mount path for which you wish to view the content, and then click View Contents.
or

From the Media Used By Job ID dialog box right-click the media for which you wish to view the content, and then click View Contents.
The Contents of Media dialog box displays the details of jobs available in the media.

Delete the Contents of a Mount Path

Required Capability: Capabilities and Permitted Actions

To delete the contents of a mount path:

From the CommCell Browser, right-click the mount path for which you wish to delete the contents, and then click Delete Contents.
Click Yes in the Warning prompt to continue.
Click No to abort the operation.
In the Enter Confirmation text dialog box, type erase and reuse media and then click OK.
Click Cancel to abort the operation.

NOTES

This operation deletes the data from the CommServe database. Note that this operation does not free-up the disk space in the mount path. A Data Aging operation must be run subsequently to free-up the disk space.

Move a Mount Path

The following procedure describes the step involved in moving a mount path currently associated with a magnetic library.

To move a mount path:

Copy the CV_MAGNETIC folder (including its contents) from the current mount path location, to the new mount path location.
From the CommCell Console: Display the Library and Drive Configuration window.
Locate the magnetic library for which you wish to move the mount path.
Right-click the mount path that you wish to move and then select Properties.
From the Mount Path Properties dialog box, enter the new path.
- If you select Local Path, click Browse to select a mount path, or enter a mount path.
- If you select Network Path, type the user name and password to access the network share. Click Browse to select a mount path, or enter a mount path.
Click OK to save the information.
The mount path is moved to the specified location. Verify that the mount path is online and accessible after the move.

Retire a Mount Path

The following procedure describes the step involved in retiring or phasing out a mount path from a magnetic library.

To retire a mount path:

From the CommCell Browser, right-click the mount path that you no longer want to use, and then click Properties.
Click the Allocation Policy tab.
Choose the Disable mount path for write option.
Click OK to save the changes.
If necessary, create a new mount path for subsequent operations by following the procedure for Add Mount Paths.

NOTES

When you Disable mount path for write operations, the mount path will not be used for subsequent write operations. You can however perform read operations on the data available in the mount path.
Depending on the retention criteria set for the storage policy copy that was used to write the data, the data in the mount path will be pruned when data aging operation is performed.
If you wish to delete the mount path, use Valid Data in the Mount Path Properties (General) tab to determine whether the mount path has valid data.

Delete a Mount Path

A mount path can only be deleted if it does not contain backup data and is not the last remaining mount path. You can remove backup data either by deleting all storage policy copies that point to the magnetic library, or by taking the mount path offline, allowing its data to age and then running the Data Aging operation. Before you can delete a storage policy copy, all subclients associated with the copy must either be associated with a different storage policy copy or deleted.

To delete a mount path:

Delete the contents of the mount path as described in Delete the Contents of a Mount Path. Note that once data is deleted on magnetic mount paths, it will not be restorable.
Display the Library and Drive Configuration window.
Select the mount path that you want to delete, right-click, and then select Delete Mount Path.
Click OK in the prompt that appears, confirming the deletion of the mount path.
The mount path is removed from the Library and Drive Configuration window display.