CommVault Interview Questions

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

Ans: This question will be mostly asked to a CommVault experienced candidate. The answer should include the number of Prod CommServe, DR CommServe, Media Agents, etc. Mention about 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;

• User needs to check the available free space regularly and also mention the remaining space available in the disk libraries.
• Extract the backup report which is already failed and analyze the issue. All you need to do is the rectification the process.
• Check regularly for deployment, decommissions, and restores the requests.
• You need to check for the media agent when they are not in offline mode.

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 get access to reports, go to the web console by hitting the URL in a browser. Log into your account and click on 'Reports'. In the case of a private metrics reporting server, you will be able to view the reports in the CommCell console.

28.What are the types of backups available in CommVault

Ans: Commvault provides efficient backup and restores functionalities for any enterprise. These are the types of backups available in CommVault,

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

29. 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 to it. Both snapshots and clones are considered a good approach to disaster recovery.

30. 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 and this software can be used independently based on one’s requirement.

31. How you configure a cluster backup?

Ans: 

The steps are as follows;

1. Create the cluster group -> add the client machines -> perform sync.
2. For the windows software (Commvault) installation -> you need to prompt the passive node.
3. Then perform installation -> schedule backup.commvault advaced interview questions

C. Commvault Advanced Interview Questions

32. Explain about Intellisnap?

Ans:  Intellisnap backup is used to create a point-in-time snapshot of the data. It is mainly used for taking backup of live data and then continuing the live operations. 

33. Explain about IRM

Ans: IntelliSnap recovery manager (IRM) is used to execute hardware storage systems snapshots into a recovery process with no effect on the production server. It also provides a centralized configuration wizard through which we can configure storage media, policies, etc.

34. 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 -> then select the virtualization- client->virtual server -> VMware -> backup-set.
• Now right click on a sub-client -> click on the backup option -> here you need to select any one backup type such as full, incremental, or differential backups.
• 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 -> click configure -> specify the task -> click ok.
• Click on home -> job controller -> then track the progress of the job.

35. Explain the steps involved in creating the CommVault proxy?

Ans: The below steps explains 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 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.

36. What is the process that happens in backup copy operations in 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, so the required contents can be read

• The primary copy will be used to perform the file system backup

• After the backup job is done, the snapshot will be unmounted

37. How can we use a specific set of tapes for a server backup?

Ans: We have to create a new scratch pool and add the media to it. Attach a subclient to the scratch pool. This can be done at two levels,

• Storage policy level
• Copy policy level

38.Explain about Silo in CommVault

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

39.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 as that of the database
• A snapshot is a copy of a database at a particular timestamp. We should take a subsequent snapshot if there are any changes made to the database. When we want to restore data, we will have a restore point to get the data from a certain point in time

40. Explain the ways to restore data using CommServe?

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

• Here user can directly restore the backup data from a DR export file location
• By retrieving the data that is present in the disk or tape backup and then restoring the DR data.

41. How does CommVault work?

Ans:

• CommVault software tools contain the advanced modules which are used for data protection, analyzing the duplicate data, and searching the data. All these advanced modules share the same set of back-end services and also offer advanced capabilities to interact with each other

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

42. Explain about Global Dedup Storage Policy?

Ans: The global deduplication policy furnishes a common deduplication database(DDB) that can be shared by various storage policy copies. It allows the deduplication of data from multiple copies which results in removing redundant data.

43.Explain briefly about storage policy?

Ans: A storage policy in CommVault is a data management entity that contains a set of rules that will be applied in lifecycle management. This supports data protection in the sub client’s contents. Storage policy also associates with the client backup to storage tape or disks and here the policy will be used to set the data retention.

44. How to access reports in CommVault?

Ans: Here users can access the reports through the cloud services portal and web console.

45. How you configure a cluster backup?

Ans: The steps are as follows;

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

46. What is the HASH algorithm?

Ans: A HASH algorithm in CommVault is used in the duplication process whenever the system reads the block of data from multiple sources and also helps to generate a unique signature.

47. Describe the key features of Commvault software?

Ans. The following are the key 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.
• Allows using 3rd party screen readers with the help of a command-line interface (CLI), web, and admin console.
• Managing Snapshot
• Managing CommCell 
• Media Operations Management
• Data Management & so on.

48. Name the different methods of doing High availability?

Ans. The following are the different methods of doing High availability in Commvault.

• Log shipping
• SQL mirroring
• Clustering SQL level

49. 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 defines data protection in the Subclient’s data. It manages and takes backup of the Subclient’s data even if it rests on other servers in Commcell.

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

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

• Standard
• Incremental
• Disaster recovery backup

50. 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.

51. Describe the various types of Copies available?

Ans. There is only one primary or synchronous copy and to that, we will be having multiple types of 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 that includes 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 full backup jobs from the main source copy. Moreover, the root copy can be a primary copy or a synchronous copy in Commvault. 

52. Explain DDB in Commvault?

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

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

53. Define the steps to configure Commvault Proxy?

Ans. To configure the Commvault Proxy on the new client, the following steps wil be helpful.

• Step1: Make a Right-click on the client system that you will use as a Commvault proxy from the Commvault browser. Then choose the properties section. 
• Step2: Click on the Network button available in the ‘Properties dialog box, and then select the checkbox - configure firewall settings.
• Step3: Now Go to the ‘Options’ tab and select “this system is in DMZ and will start working as a proxy checkbox.”
• Step4: Go to the Incoming connections tab and then select the option “add”.
• Step5: Make the selection of the “CommServe_client_name” available in the list.
• Step6: Go to the State list, select the “RESTRICTED” option and click the “OK” button.

54. What is the Commcell environment in Commvault?

Ans. A Commcell environment in Commvault is the logical arrangement of all the software components that secure, transfer, and manage data and information. This environment includes CommServe host, MediaAgent, and Clients.

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

55. How does Commvault software work?

Ans. Commvault is a data management platform that includes various modules for protecting, analyzing, duplicating, and searching data. All these modules perform the same type of back-end services with a high capacity to interact with each other continuously.

Moreover, it installs agent software on the physical or virtual hosts to safeguard data. It uses the application's native APIs or OS to safeguard data in a compatible condition Then the data is taken back up using Media Agent to the disk, tape, or cloud storage. Here, the CommServe controls the whole data management as a central server.

56. Define Silo in Commvault?

Ans. A Silo is a group of disk capacity folders related to the Deduplication Database (DDB) and it takes backup of data. It holds the de-dupe data written on the disk storage. Here, the SILO activity duplicates the folders to tape and the data stays in its de-dupe form.

57. 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. And it helps to produce a unique signature for the block data through this algorithm.

58. Mention the deduplicated storage policy’s default block size?

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

59. Define the deduplication ratio percentage that we could maintain?

Ans. Generally, we could maintain following the 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%

60. What is the place for downloading the reports in Commvault?

Ans. To download and view reports in Commvault, you can use the web console.

61. Define the way to access reports in the Commvault platform?

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

62. 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 subsequently modifies it. Moreover, both of these are considered to be good methods for disaster recovery.

63. Define IRM in Commvault and its work?

Ans. IRM refers to IntelliSnap Recovery Manager which executes hardware storage systems snapshots to a retrieval process. 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.

Below steps will present the way IRM works:

• It starts the Snapshot tasks via a schedule 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.
• Now the snapshot will provide various activities like mount/revert/restore much faster.

64. What do you mean by DDB seeding?

Ans. DDB or Deduplication Database seeding is a preset workflow that grants moving initial measure backup between two websites using a transferable disk drive.

65. What is meant by Deduplication Building Blocks?

Ans. To manage data, Commvault software runs a building block method which is a group of servers and storage that protects data sets irrespective of the data type or its origin.

DBB or Deduplication Building Blocks helps to safeguard large-size data with the least framework, faster backups, and better reliability.

66. Commvault is an Enterprise-Level software-Is it?

Ans. It is true that Commvault is an enterprise-level software. Commvault is a very simple platform to use and it is developed from scratch and includes multiple modules. They can be used independently as per the requirement. 

67. Define the Backup work in Commvault?

Ans. Commvault software offers the most effective, well-organized backup and restores enterprise data from common applications, OS, and databases. For data backup, it uses agents or factors to connect with apps or files. Also, it eases data transfer from production machines to secured environments.

The following are the different types of backups we get in Commvault:

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

68. Define Continuous Data Replicator (CDR) in Commvault?

Ans. The CDR helps to duplicate data from the source files to the target. It safeguards data and offers recovery support for different types of data which includes application data and file systems.