Commvault

Disk Storage - Commvault Command Center

Owned by Carl Brault (Unlicensed)
Last updated: Nov 30, 2021 by tdopko@commvault.com (Unlicensed)
7 min read

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Great thanks to Mike Byrne for his hard work with the screen captures.

Storage Configuration Overview

Commvault® software logically addresses storage systems to allow virtually any storage target to be used. The three primary target types are disk, tape, and cloud. 



Disk Storage

A Commvault® disk storage is a logical container which is used to define one or more paths to storage called backup locations (mount paths). These paths are defined explicitly to the location of the storage as a drive letter or a UNC path. Within each mount path, writers are allocated which defines the number of concurrent streams for the mount path.

There are two primary types of disk storage:

  • Dedicated disk storage is configured by clicking Add Storage and selecting Disk from the list. One or more backup locations can be created/added to the disk storage. Backup Locations are configured as Shared Disk Devices. The Shared Disk Device in a dedicated disk storage has only one Primary Sharing Folder.
  • Shared disk storage is a target with more than one Primary Sharing Folder configured on a Shared Disk Device. This enables other MediaAgents access to the same shared volume resource. CIFS protocol is used to manage multiple MediaAgent access to the same directory. For UNIX hosted MediaAgents, Network File System (NFS) protocol can be used. NFS shared disks appear to the MediaAgent as local drives.

There are three methods that disk storage can be configured:

  • Network Attached Storage or NAS
  • Storage Area Network or SAN
  • Direct Attached Storage or DAS

Disk storage best practices:

  • If using DAS or SAN, format mount paths (backup locations) using a 64KB block size.
  • If using DAS or SAN, try to create multiple backup locations (mount paths). For instance, if there are 10 mount paths, and there is a maintenance job, such as a defrag job running on one, the mount path can be set to read-only, leaving 90% of the storage available for backup jobs.
  • Share the disk storage if required.

The following explanations assume Commvault deduplication is being used.


Network-Attached Storage (NAS)

Network-Attached Storage provides the best connection method from a resiliency standpoint since the storage is accessed directly through the NAS device. This means that by using a Common Internet File System (CIFS) or a Network File System (NFS), Universal Naming Convention (UNC) paths can be configured to read and write directly to storage. In this case, the target can be configured as a shared disk storage, where all MediaAgents can see stored data for data protection and recovery operations.

Disk storage using Network Attached Storage (NAS)




Storage Area Network (SAN)

Storage Area Networks or SANs are very common in many data centers. SAN storage can be zoned and presented to MediaAgents using either Fibre Chanel or iSCSI. In this case, the zoned storage is presented directly to the MediaAgent providing Read / Write access to the disks.

When using SAN storage, each building block should use a dedicated MediaAgent, DDB and Commvault® disk storage. Although the backend disk storage in the SAN can reside on the same disk array, it should be configured in the Commvault® software as two separate Commvault® disk storage; where Logical unit numbers (LUNs) are presented as mount paths (backup locations) in dedicated targets for specific MediaAgents.


Disk storage using Storage Area Network (SAN)




Direct Attached Storage (DAS)

Direct attached storage is when the disk storage is physically attached to the MediaAgent. In this case, each building block is completely self-contained. This provides for high performance but does not provide resiliency. If the MediaAgent controlling the building block fails, data stored in the disk storage cannot be recovered until the MediaAgent is repaired or replaced. Keep in mind that, in this case, all the data in the disk storage is still completely indexed and recoverable, even if the index directory is lost. Once the MediaAgent is rebuilt, data from the disk storage can be restored.

Disk storage using Direct Attached Storage (DAS)



Add a Disk Storage

Before adding a Commvault® disk storage, the operating system must have access to the storage. For SAN or DAS storage, volumes must be created and formatted in the operating system. For NAS, try to access the storage CIFS shares using the credentials.

Once the operating system has access to the storage, the Commvault® disk storage can be created.




To add a disk storage

1 - Expand Storage | Disk.

2 - This window displays the disk storage currently configured in the CommCell® environment.

3 - Click Add to add a disk storage.



4 - Provide the name for the new disk storage.

5 - Click Add to add storage.



6 - Select the MediaAgent used to reach the target storage.

7 - Select Local path for DAS and SAN targets or Network path for NAS targets.

8 - Browse to the location of the first backup location (mount path).

9 - Enable/disable deduplication for the disk storage.

10 - Click to create the disk storage.



11 - Click Save to complete the disk storage configuration.


Add Backup Locations to the Disk Storage

Creating the disk storage also defines the first backup location (mount path). Any additional backup location will need to be defined.




To add a backup location to a disk storage

1 - Expand Storage | Disk.

2 - This view displays the disk storage currently configured in the CommCell® environment.

3 - Click the name of the disk storage for which you want to add a mount path.



4 - This section displays usage information.

5 - This section displays mount path information.

6 - Click to add a new mount path.



7 - Select the MediaAgent having access to the mount path.

8 - Choose to use a local or network path.

9 - Browse for the mount path location.

10 - Click to add the mount path.


Share the Disk Storage

If the Commvault® storage is using NAS storage, it can be shared with other MediaAgents. Sharing storage is achieved by sharing its backup locations. Apply the sharing procedure on each backup location (mount path).

Note that before sharing the backup locations, the credentials used to access the NAS storage must first be configured in the Credential Manager applet.



Configure the Credentials in Credential Manager




To configure credentials

1 - Expand Manage.

2 - Click System.

3 - Click Credential manager.



4 - Click Add.



5 - Provide a descriptive name for the credential.

6 - Enter a security account from the account type selected.

7 - Select the CommCell® user account to be owner of the credentials.

8 - Select the CommCell® security group which is allowed to manage the credential.

9 - Click Save to create the new credential.


Share the Disk Storage




To share a disk storage

1 - Expand Storage | Disk.

2 - Displays the disk storage currently configured in the CommCell® environment.

3 - Click the name of the disk storage for which you want to share the backup locations (mount paths).



4 - Configured backup location (mount paths) are displayed.

5 - Click the name of the first backup location.



6 - This view displays the paths accessing the disks. In this example, only one MediaAgent has access to the disk.

7 - Click Add MediaAgent.



8 - Select the MediaAgent with which the backup location (mount path) will be shared.

9 - Click Save to add the MediaAgent.



10 - The second access path is added to the list. Repeat the same process to all other backup locations.


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