Top Commvault Interview Questions and Answers for 2023 - IQCode

Overview of Commvault Software

Commvault is an enterprise-level data platform that provides modules for backup, restoration, archiving, replication, and search functionalities. It is developed with a uniform codebase from scratch. The software has four product lines - Complete Backup and Recovery, HyperScale integrated appliances, Orchestrate disaster recovery, and Activate analytics. Commvault can be deployed on both cloud or on-premises settings.

The installation of the Commvault agent software ensures the protection of data on physical or virtual hosts. The software uses the operating system or application native APIs to keep the data in a consistent state. The production data on client PCs is processed by the agent software and backed up to disk, tape, or cloud storage through the MediaAgent data manager. A central server called CommServ tracks all data management activities in the environment which can be managed by administrators via a central user interface. Commvault software can be accessed through web browsers and mobile devices from any location.

Commvault debuted a remote operations management service for storage management aimed at small and medium-sized businesses in 2008. In 2009, the Simpana version 8 of the backup software product was released, which was the first to offer worldwide embedded software deduplication, allowing data deduplication regardless of storage location. Simpana was later rebranded as Commvault Software in 2015 following the release of version 10. Commvault started selling its Hyperscale Backup data protection appliances in 2017, with the high-capacity Hyperscale appliances and the standalone Remote Office Appliance added a year later. In 2017, Cisco Systems and Commvault introduced ScaleProtect, which provides enterprise customers with a cloud-like, on-premises solution for secondary data management by combining the HyperScale software reference architecture with the Cisco Unified Computing System.

On July 17, 2018, Commvault Complete Backup & Recovery, Commvault HyperScale, Commvault Orchestrate, and Commvault Activate were introduced as a newly bundled set of four solutions under the name Commvault Complete. Metallic, a SaaS backup and recovery service for the mid-market, was introduced on October 14, 2019, which allows users to back up on-premises data to their own backup system, their public cloud, Metallic's public cloud, or a combination of both.

In this article, we have compiled some of the most popular interview questions related to Commvault.

Commvault Interview Questions for Freshers

1. What is Commvault Software, and what are its key features and benefits?

Advantages of Using Commvault

Commvault offers several advantages, including:

- Efficient data management: Commvault allows users to manage their data more efficiently by streamlining processes and reducing the need for multiple tools. - Comprehensive data protection: With Commvault, users can protect all types of data, including virtual, physical, and cloud data. - Simplified disaster recovery: Commvault automates and simplifies the disaster recovery process, making it faster and more reliable. - Improved data visibility: Commvault's reporting and analytics tools provide users with valuable insights into their data, helping them make more informed decisions. - Flexibility: Commvault can be customized to meet the specific needs of different organizations, making it a versatile solution for data management.

Key Features of Commvault

Commvault is a comprehensive data management software that offers several key features:

<ul>
  <li>Backup and recovery of data across various devices and platforms</li>
  <li>Disaster recovery capabilities</li>
  <li>Data deduplication to reduce storage needs</li>
  <li>Cloud integration for backup and storage</li>
  <li>Data archiving for long-term retention and compliance</li>
  <li>Automated data replication and migration</li>
  <li>Easy-to-use user interface</li>
  <li>Advanced reporting and analytics</li>
  <li>Flexible deployment options</li>
</ul>

These features make Commvault a reliable and versatile solution for managing data in various enterprise environments.

Understanding Commvault's Deduplication Database

Commvault's deduplication database is a unique feature that helps reduce the amount of storage space required for backups by identifying and eliminating duplicate data. This database stores the unique pieces of data that have been previously backed up, so when a new backup is performed, Commvault compares the data to the deduplication database and only backs up the new or changed data.

This process helps to reduce the amount of storage space needed for backups, which can be a significant cost savings for organizations. In addition to reducing storage costs, the deduplication process can also help to improve backup and recovery times, as there is less data to transfer and process.

Commvault's deduplication database is fully integrated into its backup and recovery solutions, making it a powerful tool for organizations looking to streamline their backup processes and save on storage costs.

Types of Transport Modes Supported by VMware

VMware supports different transport modes for the communication between virtual machines (VMs) and their hosts, including:

- Bridged Networking
- NAT (Network Address Translation)
- Host-Only Networking
- Network Address Translation (NAT)
- Custom Networking


Each mode has its own advantages and disadvantages. Bridged networking, for example, allows VMs to connect to the external network and get their own IP addresses, while host-only networking provides a private network between the VMs and the host machine. Custom networking mode, on the other hand, allows users to customize the network configuration according to their specific needs.

List of Daily Tasks for Backup Administrator:

- Verify that scheduled backups were completed successfully.
- Monitor backup storage resources and ensure adequate space is available for future backups.
- Perform backup verification and testing to ensure data can be restored in case of disaster.
- Troubleshoot and resolve backup failures.
- Update backup schedules as needed to reflect changes in data or system configurations.
- Ensure that backup processes adhere to industry-standard security and compliance requirements.
- Develop and maintain backup and disaster recovery documentation.
- Coordinate with other IT staff to ensure that backup procedures are integrated with other system processes.
- Evaluate and implement new backup technologies and processes to improve efficiency and reliability.
- Provide backup-related support and assistance to end-users as needed.

Common Backup Failures

What are some of the most common backup failures that one can encounter?

Explaining Commvault Terminology

1. IRM CommCell: This refers to the instance of the CommCell environment that has been configured to support Information Rights Management (IRM) for secure data access and control.
2. CommServe: This is the centralized management entity within the CommCell environment that coordinates activities such as backups, recoveries, and disaster recovery processes.
3. CommServe Database: This contains all configuration information for the CommCell environment, including clients, storage policies, schedules, and more.
4. CommCell Console: This is the graphical user interface used to access and manage the CommCell environment. It provides administrators with a comprehensive view of their data protection infrastructure.
5. MediaAgent: This software component manages the movement of data between the CommCell environment and the storage media, such as disk or tape. It also performs tasks such as data deduplication and compression.
6. IRM Clients: These are the users who are authorized to access data that has been secured with Information Rights Management. They use an IRM client application to access protected data.

Default Block Size for Deduplicated Storage Policy

In a deduplicated storage policy, the default block size is typically 8 KB. However, this may vary depending on the specific deduplication technology being used. It is important to note that this default block size can be changed if it is deemed necessary for a particular use case.

Understanding Commvault Snapshots and their Advantages

In the context of Commvault, a snapshot refers to a read-only copy of data at a given point in time. Snapshots allow for quick access to data backups without disrupting ongoing operations. They are created by capturing the state of a file system at a particular moment, and then saving that state for future reference.

There are several advantages to using snapshots in Commvault. Firstly, they provide a way to quickly recover data in the event of an outage or data loss, as they offer a point-in-time view of the data. Secondly, snapshots can be used to facilitate backups and archiving, making the data protection process more efficient. Finally, they can help to minimize downtime during maintenance and updates, as data can be accessed and backed up without any impact to live operations.

Overall, Commvault snapshots are a valuable tool for data protection and management, offering speed, flexibility, and improved data availability.

Differences between Snapshot and Backup

Snapshots and Backups are both commonly used methods to save copies of data to restore systems in case of failure. However, there are some significant differences between them:

• Snapshot: A snapshot is a copy of the current state of a virtual machine (VM) at a specific point in time. It captures the contents of memory, virtual devices, and settings of the VM at the time the snapshot is taken. Snapshots are used to revert a VM to an earlier state when something goes wrong.
• Backup: A backup is a copy of data that is made for the purpose of being reused or restored in case the original data is lost or damaged. Backups normally contain all data in a system, including files, folders, databases, and applications, and can be restored to any point in time.

While both Snapshots and Backups provide a safety net against data loss, it is essential to understand what each method does and how they work in your environment.

// Sample code for taking a snapshot in VMware using vSphere PowerCLI
Get-VM VMName | New-Snapshot -Name "Snapshot Name" -Description "Snapshot Description"

Identifying if a Job has Been Encrypted

In order to determine if a job has been encrypted, you can look for specific telltale signs. If the job is encrypted, you will likely see a lock icon on the job file, indicating that it is not accessible. Additionally, you may encounter a message that states the job cannot be accessed or modified due to encryption.

One way to check if a job is encrypted is to look at the file extension. Encrypted jobs may use a different file extension than regular jobs. For example, a regular job may have a ".txt" extension, while an encrypted job may have a ".enc" extension.

Another way to identify encrypted jobs is to try opening the file with a text editor. If the file contains gibberish or random characters instead of readable text, it could be encrypted.

If you are still unsure whether a job is encrypted, you can try contacting the person who sent the file or the company that created it for clarification.

Performance impact of Encryption

What is the extent of performance impact caused by encryption?

Key Backup in the Event of a Disaster

In case of a disaster, it's crucial to have a backup of your keys. There are a few methods to backup keys, including:

1. **Printed Copy**: You can print out a paper copy of your private key and store it in a secure location. This method is safe from hackers, but you need to be careful not to lose or damage the paper.

2. **USB Drive**: You can save a copy of your keys on a USB drive and keep it in a safe location. However, there is a risk of the USB drive being damaged, lost, or stolen.

3. **Cloud Storage**: You can store a backup of your keys in the cloud. This method is convenient, as you can access your keys from anywhere. However, it comes with a risk of the cloud service being hacked.

It's recommended to use a combination of these methods to ensure the safety of your keys in case of a disaster. Additionally, you should periodically test your backup methods to make sure that they are working properly.

Ownership of Encryption Keys

In terms of ownership, who possesses the encryption keys?

Location of Pass Phrases in Commvault

The location of pass phrases in Commvault depends on the type of encryption being used. Typically, pass phrases for disk encryption are stored in the CommServe database, while pass phrases for tape encryption are stored on the MediaAgents that perform the encryption. It is important to ensure that proper security measures are in place to protect these pass phrases from unauthorized access.

Commvault Interview Questions for Experienced

Question 17: What events are triggered during a Deduplication Database (DDB) backup process?

During a Deduplication Database (DDB) backup process, the following events are triggered:

• The DDB is scanned for a list of protected and aged jobs that can be backed up.
• A checkpoint is created to persist the current state of the DDB.
• The valid data blocks are read, and the corresponding storage information is backed up.
• The list of backed up blocks is updated in the DDB's extent list.
• The Deduplication Index Cache (DIC) is updated with the changes made to the DDB during the backup process.
• The DIC is flushed to disk to persists the changes.
• The checkpoint created in the beginning is updated to show that the DDB has been backed up successfully.

Explanation of Terminologies in the Context of Commvault

Storage Policy: A storage policy is a set of rules that determine where the backup data will be stored, for how long, and how many copies will be retained.

Job Manager: The Job Manager is responsible for scheduling and managing backup and restore jobs across the Commvault environment.

Backup Set: A Backup Set is a grouping of data that needs to be backed up together. It can include files, folders, databases, or entire systems.

Subclient: A Subclient is a subset of data within a backup set that can be backed up or restored independently. It can provide more granular control over backups and restores.

Collect Files: Collect Files is a tool within Commvault that allows you to gather files from various locations and transfer them to a central location for backup. It's useful for environments where data is stored across multiple servers.

Difference between a Snapshot and a Clone of a Virtual Machine

In the context of virtualization, a snapshot is a state of a virtual machine at a specific point in time. A snapshot captures the current memory, disk, and device state of the virtual machine, enabling an administrator to revert back to that snapshot at any point.

On the other hand, a Clone is an exact copy of a virtual machine. It's like creating multiple virtual machines from the same virtual machine template. When a virtual machine is cloned, it has a new identity with its own MAC address and UUID.

In summary, while a snapshot is merely a picture of a virtual machine at a specific moment in time, a clone is a complete copy of the virtual machine that can function as an independent machine.

Is a Certificate Authority Necessary for Encryption in Commvault?

In Commvault, a Certificate Authority (CA) is not mandatory for encryption, but it is recommended for optimal security. Without a CA, self-signed certificates can still be used for encryption, but they may not provide the same level of trust and authentication as certificates issued by a trusted CA. Ultimately, the decision to use a CA for encryption in Commvault should be based on the specific security requirements of the organization.

Effect of Encryption on Compression when Writing to the Media

When writing data to the media and applying encryption, it is possible for encryption to have an effect on compression. This is because encryption can make the data appear more random, which reduces the redundancy and compressibility of the data.

However, modern compression algorithms are designed to work with encrypted data, and they can still achieve some level of compression even when the data is encrypted. Therefore, the extent to which encryption affects compression depends on the specific encryption and compression algorithms used.

Data Encryption during Backup and Offline/Auxiliary Copy in API

In case data encryption is enabled during backup and offline/auxiliary copy, the data is encrypted only once. There is no second encryption performed on the data.

How Keys are Stored in the CommServe Database?

In the CommServe database, keys are stored in a specific way.

Different Types of Copies in CommVault and Their Meanings

In the context of CommVault, there are three main types of copies: full, incremental, and synthetic full.

1. Full Copy: A full copy is a backup of all the selected files and data. It is the largest type of copy and requires the most time and storage space.
2. Incremental Copy: An incremental copy only backs up the changes in data since the last backup. It is smaller and faster than a full copy, but requires the original full copy to be restored in order to access all data.
3. Synthetic Full Copy: A synthetic full copy is a combination of a full copy and one or more incremental copies. It creates a new full backup without actually copying all data. This method saves time and storage space while still creating a complete backup.

Understanding these different types of copies is important for efficient data backup and recovery. It allows for the selection of the most appropriate method based on the available storage space, time constraints, and data importance.

Frequently Asked Questions

25. What is your reason for wanting to join Commvault?

How to Access Commvault

If you want to access Commvault, you can follow these steps:

1. Visit the Commvault website
2. Click on the login/register button
3. Enter your login credentials if you already have an account, or register for a new account
4. After logging in, you can access the features provided by Commvault

Commvault: A Product-Based Company?

As per my understanding, Commvault is primarily a product-based company. It specializes in providing software solutions for data backup, recovery, and management. Their flagship product, Commvault Complete Backup & Recovery, is widely used in businesses worldwide. Additionally, they offer various other products and services related to data management, including Commvault HyperScale, Commvault Orchestrate, and Commvault Activate. So, in short, Commvault is indeed a product-based company.

Salary of Commvault Software Developers in India

As per available information, what is the salary of software developers working at Commvault in India?