40+ Vmware Administrator Interview Questions and Answers

All path down is a condition where all paths to a storage device become unavailable. Permanent device loss refers to a situation where a storage device is permanently inaccessible.

• All path down occurs when all paths to a storage device fail, resulting in loss of connectivity.

• Permanent device loss happens when a storage device becomes permanently inaccessible due to hardware failure or other issues.

• To troubleshoot all path down, check the host logs for any error messages relat...read more

FSMO role in Windows Server, cloud types, resource allocation, VM creation, utilization check, VSAN, hybrid and all-flash explained.

• FSMO (Flexible Single Master Operations) role is a set of 5 operations master roles in Windows Server

• Public cloud is owned by a third-party provider, private cloud is owned by the organization, hybrid cloud is a mix of both

• Resource allocation can be done through vSphere Client or vSphere Web Client

• VMware VMs can be created through vSphere Client ...read more

To troubleshoot ESXi in a not responding & disconnected state, check network connectivity, reboot the host, and verify hardware.

• Check network connectivity to ensure the host is reachable

• Reboot the host to clear any hung processes

• Verify hardware to ensure there are no underlying issues causing the disconnect

• Check logs for any errors or warnings that may indicate the cause of the issue

DRS Affinity/Anti-affinity rules are used to control VM placement on hosts in a cluster.

• Affinity rules ensure that VMs are placed on the same host

• Anti-affinity rules ensure that VMs are placed on different hosts

• Must rules enforce the rule strictly, while should rules try to enforce the rule but allow exceptions

• Use cases include ensuring high availability, separating workloads, and optimizing resource utilization

An unresponsive VM may indicate issues like resource exhaustion, network problems, or software crashes, affecting its performance.

• Resource Exhaustion: The VM may be using all allocated CPU or memory, causing it to become unresponsive. Example: A VM running a heavy database workload.

• Network Issues: If the VM cannot communicate with the host or other VMs, it may appear unresponsive. Example: A misconfigured virtual switch.

• Software Crashes: Applications or services running insid...read more

VMware is a virtualization and cloud computing software provider. SV motion and v-motion are features that enable live migration of virtual machines. HA stands for High Availability and DR stands for Disaster Recovery.

• VMware is a software company that provides virtualization and cloud computing solutions.

• SV motion is a feature in VMware that allows live migration of virtual machines between storage devices.

• V-motion is a feature in VMware that enables live migration of virtual...read more

Virtualization is the process of creating a virtual version of a device or resource, such as a server, storage device, network or operating system.

• Virtualization allows multiple virtual machines to run on a single physical machine, maximizing resources and increasing efficiency.

• Thin provisioning allocates storage space on an as-needed basis, while thick provisioning allocates all required space upfront.

• Snapshots capture the state of a virtual machine at a specific point in ti...read more

Snapshot background process involves creating a point-in-time copy of a virtual machine's disk file.

• Snapshots are created to capture the current state of a virtual machine's disk file

• When a snapshot is initiated through vCenter or ESXi host, a background process is triggered to create the snapshot

• The background process involves freezing the virtual machine's disk file, creating a delta disk to store changes, and redirecting write operations to the delta disk

Thick provisioned eager and lazy zero are types of disk provisioning in VMware.

• Thick provisioned eager zeroed: allocates all the space for a virtual disk at the time of creation and zeros out the disk blocks immediately.

• Thick provisioned lazy zeroed: allocates all the space for a virtual disk at the time of creation but does not zero out the disk blocks until data is written to them.

Protocols used for Storage include iSCSI, Fibre Channel, NFS, and SMB.

• iSCSI (Internet Small Computer System Interface)

• Fibre Channel

• NFS (Network File System)

• SMB (Server Message Block)

Lockdown technology in VMware restricts access to the ESXi host directly, allowing only authorized users to perform specific actions.

• Lockdown mode can be enabled to prevent direct access to the ESXi host

• Only users with specific permissions can perform actions on the host

• Helps enhance security by limiting access to the host

• Can be configured through the vSphere Client or vSphere Web Client

Effective upgrade and patch management in VMware vSphere ensures system stability and security.

• Regularly check VMware's release notes for updates and patches.

• Use VMware Update Manager (VUM) for automated patch management.

• Test patches in a staging environment before production deployment.

• Schedule maintenance windows to minimize downtime during upgrades.

• Backup VMs and configurations before applying updates.

ESXi OS upgrade and rollback procedures involve careful planning and execution to ensure system stability.

• Before upgrading, ensure compatibility with hardware and software requirements

• Take backups of important data and configurations

• Use VMware Update Manager or command line interface for upgrade process

• Monitor upgrade progress and resolve any issues that may arise

• For rollback, restore from backups taken before upgrade or use snapshot feature

VSS is a virtual switch that operates at the host level, while Distributed Switch is a single switch that spans multiple hosts.

• VSS is specific to each host, while Distributed Switch is shared across multiple hosts.

• VSS is managed at the host level, while Distributed Switch is managed centrally.

• Distributed Switch allows for centralized network configuration and monitoring.

• VSS is limited to the host's physical NICs, while Distributed Switch can utilize multiple physical NICs acr...read more

DRS stands for Distributed Resource Scheduler, a feature in VMware that automatically balances resources across a cluster of hosts.

• DRS monitors resource usage on hosts in a cluster

• It automatically migrates virtual machines to balance resource usage

• Helps optimize performance and resource utilization

• Can be set to manual, partially automated, or fully automated mode

The election process in HA determines the active node in a cluster for managing resources and ensuring availability.

• In a VMware HA cluster, nodes communicate to determine which node will be the master.

• The master node is responsible for monitoring the health of other nodes and VMs.

• If the master node fails, a new election process occurs to select a new master.

• The election process uses a heartbeat mechanism to assess node availability.

• For example, if Node A fails to receive hear...read more

Check for underlying issues, restart services, verify network connectivity, review logs, escalate if necessary.

• Check for any underlying issues that may have caused the cluster to go down

• Restart the necessary services related to the cluster

• Verify network connectivity between the cluster nodes

• Review logs for any error messages or warnings

• Escalate the issue to higher level support if necessary

The vCenter patch update and rollback process ensures system stability and security through careful management of updates.

• Always back up the vCenter Server before applying patches.

• Use the VMware Update Manager (VUM) for automated patch management.

• Review the release notes for compatibility and known issues before patching.

• Test patches in a staging environment before applying them to production.

• To rollback, use the backup taken prior to the patching process.

Standard switches are local to a host, while distributed switches span multiple hosts.

• Standard switches are specific to a single host, while distributed switches can be used across multiple hosts in a datacenter.

• Standard switches are managed on a per-host basis, while distributed switches are managed centrally.

• Distributed switches offer more advanced features like Network I/O Control and LACP compared to standard switches.

• Standard switches are suitable for smaller environment...read more

Affinity and anti-affinity rules are used in VMware to control the placement of virtual machines on hosts.

• Affinity rules specify that certain virtual machines should run on the same host

• Anti-affinity rules specify that certain virtual machines should not run on the same host

• These rules help optimize performance, availability, and resource utilization

• Examples: Affinity rule for a web server and database server to run on the same host, Anti-affinity rule for redundant virtual m...read more

Snapshots can cause performance issues, take up storage space, and may not capture all changes.

• Snapshots can impact VM performance as they introduce additional overhead.

• Snapshots can quickly consume storage space, especially if multiple snapshots are taken.

• Snapshots may not capture all changes if there are active processes or open files during the snapshot creation.

• Snapshots are not a substitute for regular backups and should not be relied upon as the sole backup solution.

PSOD stands for Purple Screen of Death. It is a critical error in VMware that requires troubleshooting to fix.

• Check for hardware issues such as faulty memory or CPU

• Review system logs for any error messages leading up to the PSOD

• Update VMware ESXi to the latest version

• Check for compatibility issues with hardware or software

• Contact VMware support for further assistance

Steps to troubleshoot an unresponsive ESXi host include checking hardware, network, and logs for issues.

• Check physical hardware: Ensure all cables are connected and hardware components are functioning.

• Verify network connectivity: Use ping to check if the ESXi host is reachable from the management workstation.

• Examine logs: Access the ESXi logs (e.g., /var/log/vmkernel.log) for any error messages or warnings.

• Restart management agents: Use the DCUI to restart management agents i...read more

Admission control is a feature in Vmware that ensures resources are available for virtual machines during failover or migration.

• Admission control prevents virtual machines from being powered on if it would violate resource constraints

• It helps maintain high availability by ensuring that there are enough resources available for failover

• Admission control policies include slot policy, dedicated failover hosts, and resource pools

Admission control rules ensure resource availability for VMs during failures in a VMware environment.

• Admission control prevents VMs from being powered on if resources are insufficient.

• It can be configured to reserve a percentage of cluster resources for failover.

• Example: If a cluster has 10 hosts and 2 are reserved for failover, only 8 hosts are available for VMs.

• Different policies include 'Percentage of cluster resources' and 'Host failures cluster tolerates'.

• Admission contr...read more

Memory ballooning is a memory reclamation technique used in virtualization to reclaim memory from virtual machines.

• Memory ballooning is a technique used by hypervisors to reclaim memory from virtual machines by inflating or 'ballooning' a balloon driver inside the guest OS.

• The hypervisor can then allocate this reclaimed memory to other virtual machines that need it more.

• Memory ballooning is typically used when the host is under memory pressure and needs to reclaim memory from...read more

The purpose of VMware is to provide virtualization solutions for businesses to optimize their IT infrastructure.

• VMware allows businesses to create virtual machines, which are software-based replicas of physical servers, storage devices, and networks.

• It helps in reducing hardware costs by consolidating multiple virtual machines on a single physical server.

• VMware enables businesses to improve efficiency, flexibility, and scalability of their IT infrastructure.

• It also provides f...read more