CommVault Interview Questions

1) What is CommVault?

Ans: CommVault is a data protection and information management platform with HQs in Tinton Falls, New Jersey. It helps organizations access, protect, and use all their data to its actual value. CommVault also performs data backups and recovery.

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2) What do you mean by the CommVault tool?

Ans: CommVault is an information and management solution that protects and manages your business data. It is a publically traded software company founded in 1988 and located in the USA. This software can be used for data backup, recovery, and cloud management. It was formerly known as Simpana.

3) What are the ways of achieving high availability?

Ans: There are three ways of achieving high availability (HA) in CommVault, such as:

Log Shipping

• SQL Mirroring
• Clustering at the level of SQL

4) What are the features of the CommVault software tool?

Ans: The following are the key features of CommVault;

• It offers efficient storage management with the help of duplication for disk and tape.
• It provides simplified management via a single console system.
• It offers complete data protection and security.
• Its command-line interfaces, web consoles, and admin console management help users use third-party screen readers.
• It offers snapshot management and edge endpoint solutions.
• CommCell, data, and media management are also possible.

5) What are the other ways of doing high availability?

Ans: There are various ways of performing high availability (HA) in CommVault, such as:

• Log shipping
• SQL mirroring
• Clustering SQL level

6) What is the HASH algorithm?

Ans: In CommVault, a HASH algorithm is used in the deduplication process whenever the system reads a block of data from multiple sources, helping produce a unique signature.

7) What are the copies, and what are they?

Ans: In CommVault, we can see only one Primary copy and different auxiliary/secondary copies, such as;

• Selective copy: This copy type allows users to copy the specific backup system tools from different sources. The source copy can be either primary or synchronous.
• Inline copy: This type of Copy allows you to perform both primary and secondary copy tasks to store the backup phase.
• Synchronous copy: All the primary data can be copied on this copy.

8) Explain the types of copies in CommVault.

Ans: We will have the primary and secondary data. We can create three types of secondary copies:

• Synchronous secondary copy - It includes data from a source copy.
• Selective secondary copy - It includes valid full or synthetic full backup data.
• IntelliSnap backup copy - It manages the control of snapshots, which are started by a backup job. It contains archived index data.

9) What are CommServe DR procedures?

10) What is the global Dedup security policy?

Ans: This global duplication policy enables data duplication across the multiple storage sets of disk libraries and database servers (DDB).

11) What is DDB in CommVault?

Ans: The following factors will give a brief explanation of DDB:

• DDB is an efficient way to transmit and store data, which is possible by detecting and eliminating duplicate data blocks.
• DDB backup sub-client methods protect the DDB system.
• When you create the storage policy using duplication data, a DDB backup will be created automatically under the file management system agent on the media client.

12) What are the main components of the CommCell environment?

Ans: There are three building blocks of the CommCell environment;

• CommServe: The central management component executes all the CommCell data operations.
• Media Agent: A data transmission manager system enables high-level data movement performance and handles the data storage packages.
• Client: A client is a logical group of data agents that perform tasks like data protection, management, and movement of data association.

13) What are the uses of the proxy server?

Ans: The benefits of a proxy server such as;

• A proxy server is used to access the storage array, which is used to create a snapshot.
• The snapshot is built on the ESX server designated for the snap mount.
• It helps to unmount the snapshots.
• The mounted snapshot is treated as a file system, and the required content will be read.
• The file backup acts as a primary copy of the storage policy.
• When the backup task is finished, the snapshot is unmounted.

14) What are the entities that get backed up with VMWare backups?

Ans: We can perform a backup on VMWare from a subclient. The entities that get backed up are are as follows:

• Windows and Linux virtual machines 
• VM templates
• VMDK files
• Virtual RDMs
• GPT or dynamic disk volumes
• vSphere tags
• Fault-tolerant VMs

15) What are the types of transport modes available for VMWare backup?

Ans: The data of a Virtual Machine can be accessed by a VMware Backup Host using four methods,

• SAN - VMware Backup Host should reside on a physical machine and be able to access Fibre Channel or iSCSI SAN.
• LAN - The data from storage will be read by the ESX/ESXi host and sent to the VMware Backup Host through a network.
• HotAdd - If the VMware Backup Host is on a VM, we can use HotAdd to attach the VMDKs of the Virtual Machine that is being backed up to the VMware Backup Host.
• NBDSSL works similarly to LAN. However, unlike LAN, NBDSSL uses SSL encryption for all data passed through a TCP/IP connection.

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16) What are CommVault Appliances?

Ans: CommVault HyperScale Appliance provides seamless scale and data protection solutions. It is mainly used for scaling out infrastructure with cloud-like economics. It is a storage architecture that offers a platform for indexing, storage, data security, automation, reporting, etc.

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17) What is DDB seeding?

18) What is the default block size for duplication?

Ans: The default block size for the data duplication is 128kb.

19) What are Synthetic Full, Full backup, and Dash Full?

• Synthetic Full: Synthetic full backup consolidates all the data incremental backups and appends the last backup data. Here, the server (server is nothing but client machine or network utilization) performs at very low utilization compared to full backup.
• Full Backup: The full backup performs a full utilization operation taken from the server.
• Dash Full: The dash full performs operations like copying the unique blocks of the de-duplicate data, updating the DDB data, and indexing the backup data.

20) What is SILO?

Ans: A silo is the collection of disk volume data folders that are associated with the DDB (De-Duplicate database). It contains deduplicated data that is pre-written for disk storage.

21) Name the various types of backups available in CommVault.

Ans: The following are the different backups available in CommVault;

• Full Backup
• Incremental Backup
• Differential Backup
• Synthetic Full Backup
• Selective Online Full Backup
• Block-Level Backup

22) Name the different types of transfer modes available for CommVault.

Ans: The different kinds of transfer modes are such as;

• Transport mode SAN (storage area network)
• Data can be accessed directly when located in a VMware host, or we can call it LUN.
• Hot add transfer mode
• Local area network (NBD and NBDSSL) transfer mode

23) What is CommVault Simpana?

24) Tell me about the infrastructure that you worked on previously.

Ans: This question will mostly be asked of a CommVault experienced candidate. The answer should include the number of Prod CommServe, DR CommServe, Media Agents, etc. Mention all the backup servers that you have used.

25) List all day-to-day activities of a backup admin.

Ans: The following are the operations performed by the users;

• The user must regularly check the available free space and mention the remaining space in the disk libraries.
• Extract the failed backup report and analyze the issue. All you need to do is correct the process.
• Check regularly for deployment and decommissions and restore the requests.
• You need to check for the media agent when they are not offline.

26) What is the process of moving DDB to a new media agent?

Ans:  The following steps explain the process;

Step 1: Go to -> Deduplication engines -> under the storage resources

Step 2: now choose the DDP that you want to move -> then right-click on it -> click on move partitions

Step 3: Now choose the new Media agent option that is available in the target media agent.

27) How can we access reports in CommVault?

Ans: To access reports, go to the web console by hitting the URL in a browser. Log into your account and click on 'Reports.' You can view the reports in the CommCell console if you have a private metrics reporting server.

28) What is the difference between a Snapshot and a clone?

Ans: Cloning is used to make a copy of something, whereas a snapshot makes an initial copy and then adds subsequent changes. Both snapshots and clones are considered good approaches to disaster recovery.

29) Is CommVault enterprise-level software?

Ans: The answer is yes. It is enterprise-level software. Using this CommVault software, we can build the data modules from scratch, which can be used independently based on one’s requirements.

30) How do you configure a cluster backup?

Ans: The steps are as follows;

• Create the cluster group -> add the client machines -> perform sync.
• For the Windows software (Commvault) installation -> you need to prompt the passive node.
• Then perform installation -> schedule backup.

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31) Explain about Intellisnap?

Ans: Intellisnap backup creates a point-in-time snapshot of the data. It is mainly used to back up live data and continue live operations.

32) Explain about IRM.

Ans: The IntelliSnap recovery manager (IRM) executes hardware storage systems snapshots into a recovery process without affecting the production server. It also provides a centralized configuration wizard to configure storage media, policies, etc.

33) How to perform a VMware backup?

Ans: The below-mentioned steps will help you perform a VM ware backup:

• First, navigate to the client computers from the CommCell console and select the virtualization option —client->virtual server -> VMware -> backup-set.
• Now right-click on a sub-client, click on the backup option, and select one of the backup types, such as full, incremental, or differential.
• If you want to modify the backup -> go to default modify settings -> then click on the advanced.
• If you want to run any program immediately, click on immediate, configure, specify the task, and click OK.
• Click on home -> job controller -> then track the job's progress.

34) Explain the steps involved in creating the CommVault proxy.

Ans: The below steps explain the steps involved in creating the CommVault proxy;

• Step-1: Right-click on the client computer -> from the CommVault browser -> select the properties

• Step 2: Go to the properties dialog box -> click on the network button -> select the configuration firewall settings -> select the checkbox

• Step-3: Now click on the options tab -> choose the “computer is in DMZ and this will work as a proxy checkbox.

• Step-4: Click on the incoming connection option -> now select the add

• Step-5: Select the Commserve_client_name from the list

• Step-6: From the list -> select the Restricted -> click OK.

35) What process happens in backup copy operations within the proxy server?

Ans:

• The snapshot will be mounted to the ESX server.
• Once the snapshot is mounted, it will be treated as a file system to read the required contents.
• The primary copy will be used to perform the file system backup.
• After the backup job is done, the snapshot will be unmounted.

Advanced CommVault Interview Questions

36) How can we use a specific set of tapes for a server backup?

Ans: We must create a new scratch pool and add the media. Attach a subclient to the scratch pool. It can be done at two levels:

• Storage policy level
• Copy policy level

37) Explain about Silo in CommVault.

Ans: A set of disk volume folders associated with DDB and containing deduplication data is called a Silo. It is used to eliminate data restore from tape to disk library. 

38) Explain the difference between a Clone and a Snapshot.

Ans:

• A clone is like a duplicate of the database. It contains the exact copy of data from the database.
• A snapshot is a copy of a database at a particular timestamp. We should take a subsequent snapshot if any changes are made to the database. When we want to restore data, we will have a restore point to get the data from a specific point in time.

39) Explain the ways to restore data using CommServe.

Ans: There are two possible ways available to restore the data using CommServe;

• Here, the user can directly restore the backup data from a DR export file location.
• Retrieving the data in the disk or tape backup and restoring the DR data.

40) How does CommVault work?

CommVault software tools contain advanced modules for data protection, analyzing duplicate data, and searching data. All these advanced modules share the same back-end services and offer advanced capabilities for interacting with each other.

Here, data will be protected by installing CommVault agent software on the physical or virtual hosts that use the application's native APIs or operating systems to protect all the data consistently. This operation is controlled by a centralized server called CommServer.

41) Explain the Global Dedup Storage Policy.

Ans: The global deduplication policy furnishes a common deduplication database(DDB) that various storage policy copies can share. It allows the deduplication of data from multiple copies, removing redundant data.

42) Explain briefly about the storage policy.

Ans: A storage policy in CommVault is a data management entity containing rules that will be applied in lifecycle management. It supports data protection in the sub-client’s contents. The storage policy is also associated with the client backup to storage tape or disks, and here, the policy will be used to set the data retention.

43) How do you access reports in CommVault?

Ans: Users can access the reports here through the cloud services portal and web console.

44) How do you configure a cluster backup?

Ans: The steps are as follows;

• Create the cluster group -> add the client machines -> perform sync.
• For the Windows software (Commvault) installation -> you need to prompt the passive node.
• Then perform installation -> schedule backup.

45) What is the HASH algorithm?

Ans: CommVault uses a HASH algorithm in the duplication process whenever the system reads a block of data from multiple sources. It also helps generate a unique signature.

46) Describe the key features of Commvault software.

Ans. The following are the critical features of Commvault:-

• It offers complete data security and supports all major apps, OS, databases, and mobile devices. 
• Commvault simplifies management using a single console.
• It provides advanced security and encryption to manage data.
• It offers effective storage management using the de-dupe process for tape & disk.
• It allows third-party screen readers through a command-line interface (CLI), web, and admin console.
• It manages Snapshot and CommCell 
• It also manages Media Operations, Data Management & so on.

47) Name the different methods of high availability.

Ans. The following are the different methods of achieving high availability in Commvault.

• Log shipping
• SQL mirroring
• Clustering SQL level

48) Describe the Storage Policy in CommVault.

Ans. A storage policy in CommVault is a data management entity with a set of lifecycle management rules that define data protection in the Subclient’s data. It manages and backs up the Subclient’s data even if it rests on other servers in Commcell.

These data management rules include managing data, protecting data, determining where the data will reside, and considering other options like shortening, encryption, and eliminating duplicate data in secured storage.

Moreover, the following are the various types of storage policies in Commvault:

• Standard

• Incremental
• Disaster recovery backup

49) Define CommVault Simpana.

Ans. Simpana is one of the major features of Commvault’s enterprise data recovery platform, specially designed for backup, records, and data reporting. Moreover, it is the latest version of the Deduplication/duplicate elimination process launched by Commvault.

50) Describe the various types of Copies available.

Ans. There is only one primary or synchronous copy; we will have multiple secondary types of copies. The following are secondary copies such as:-

• Synchronous Copy: A synchronous copy automatically consists of all the valid data from a source copy.
• Snapshot Copy: Manages the task retention built by a backup job. It allows building vaults or model copies of the snapshot copy included in the server backup plan.
• Selective Copy: This copy automatically consists of valid full or specific full data recovery based on certain parameters. It also allows a user to copy specific complete backup jobs from the primary source copy. Moreover, the root copy can be primary or synchronous in CommVault. 

51) Explain DDB in CommVault.

Ans. DDB refers to the Deduplication DataBase in Commvault, where Duplication is a logical way of imparting and storing data by ascertaining and removing replicate data blocks during backups.

Moreover, the DDB is highly secured by the DDB Backup Subclient. When we design a storage policy that enables deduplication, the DDB Backup Subclient is also automatically built under the file system agent on the media client factor, where the DDBs are organized.

52) Define the steps to configure Commvault Proxy.

Ans. The following steps will help configure the Commvault Proxy on the new client.

• Step 1: From the CommVault browser, right-click on the client system you will use as a CommVault proxy. Then, choose the properties section. 

• Step 2: Click the Network button in the ‘Properties dialogue box, then select the checkbox - configure firewall settings.

• Step 3: Go to the ‘Options’ tab and select “this system is in DMZ and will start working as a proxy checkbox.”

• Step 4: Go to the Incoming connections tab and select “add”.

• Step 5: Select the “CommServe_client_name” available in the list.

• Step 6: Go to the State list, select the “RESTRICTED” option, and click the “OK” button.

53) What is the Commcell environment in CommVault?

Ans. A Commcell environment is the logical grouping of all the software elements that secure, transfer, and handle data and information. It covers CommServe host, Clients, and MediaAgent.

• CommServe is the primary management component that interrelates and performs all Commcell tasks.
• Client - It is a logical group of factors defining client data's control, security, and movement.
• MediaAgent: In the Commcell environment, MediaAgent is a data transmission manager that allows high-performance data transfer and effectively manages data storage libraries.

54) Define Hash Algorithm in Commvault.

Ans. In the deduplication process in the Commvault, a HASH algorithm is used whenever a machine reads the block data from a different source. This algorithm helps produce a unique signature for the block data.

55) Mention the default block size of the deduplicated storage policy.

Ans. The default block size is 128kb for the deduplicated (De-dupe) storage policies.

56) Define the deduplication ratio percentage that we could maintain.

Ans. Generally, we could maintain the following deduplication ratio:-

• It could be around 90% or more coming to the filing machines' backups
• But for the database backups, we could maintain it between 70% to 95%

57) What is the place to download the reports in Commvault?

Ans. In the deduplication process in the Commvault, a HASH algorithm is used whenever a machine reads the block data from a different source. And it helps to produce a unique signature for the block data through this algorithm.

58) Define the way to access reports on the Commvault platform.

Ans. Reports can be accessed through the cloud services portal and web console.

59) Distinguish between a Snapshot and a Clone.

Ans. Clone refers to making a duplicate copy of something, but a Snapshot makes a primary copy of anything and then modifies it. Moreover, both of these are considered suitable disaster recovery methods.

60) Define IRM in Commvault and its work.

Ans. IRM refers to IntelliSnap Recovery Manager, which executes hardware storage systems snapshots for retrieval. It doesn’t impact the production server in this process. Also, it provides speedy and easy backups for Snapshots, a centralized configuration wizard, and application support.

The below steps will present the way IRM works:

• It starts the Snapshot tasks via a scheduled or on-demand Intellisnap job from the Commcell console.
• Using the snapshot job, we can access the array when it begins to build the content’s snapshot.   
• Then, the snapshot is scaled for post-snap activities on the source machine.
• After the purpose is over, the snapshot is unmounted from the machine.
• The snapshot will provide various activities like mounting, reverting, and restoring much faster.

61) What do you mean by DDB seeding?

Ans. DDB, or Deduplication Database seeding, is a preset workflow that allows you to move an initial measure backup between two websites using a transferable disk drive.

62) What is meant by Deduplication Building Blocks?

Ans. Commvault software runs a building block method to manage data. It is a group of servers and storage that protects data sets irrespective of their type or origin. DBB, or Deduplication Building Blocks, helps safeguard extensive data with the minor framework, faster backups, and better reliability.

63) Commvault is an Enterprise-Level software. Is it?

Ans. Commvault is an enterprise-level software. It is a simple-to-use platform developed from scratch and includes multiple modules that can be used independently. 

64) Define Continuous Data Replicator (CDR).

Ans. The CDR helps to duplicate data from the source files to the target. It safeguards data and offers recovery support for different data types, including apps and file systems.

Conclusion

Hence, you have explored all the top CommVault interview questions in this blog. I hope you enjoyed this learning and gained a lot of skills that help you crack the upcoming interviews easily.  If you want to learn more about data management tools, keep watching this page.