Increasing Availability for Azure VMs - Availability Sets and Zones

**What is Azure Virtual Machine?**\ \ An Azure Virtual Machine is a scalable computing resource provided by Microsoft Azure, enabling users to deploy and manage virtualized instances of operating systems such as Windows or Linux in the cloud.

**What is Premium SSD?**\ \ Premium SSD is a high-performance solid-state drive (SSD) storage option in Azure that offers low-latency, high-throughput storage for mission-critical workloads. It provides consistent performance and reliability, suitable for I/O-intensive applications such as databases and large-scale virtual machines.\ \ **What is Standard SSD?**\ \ Standard SSD is a cost-effective solid-state drive (SSD) storage option in Azure, offering a balance of performance and price. It provides better performance compared to traditional hard disk drives (HDDs) while still maintaining affordability. Standard SSDs are suitable for a wide range of general-purpose workloads, offering improved performance over HDDs without the higher cost of premium SSDs.\ \ **What is Standard HDD?**\ \ Standard HDD (Hard Disk Drive) is a traditional magnetic disk-based storage option in Azure, offering the lowest cost per gigabyte of all Azure storage options. While it provides the lowest performance compared to SSD options, it still offers reliable storage for applications with less demanding performance requirements or where cost optimization is a priority. Standard HDDs are suitable for archival storage, backup solutions, and other workloads where performance is less critical.

**What is Ultra Disk compatibility?**\ \ It refers to the feature in Azure that allows virtual machines (VMs) to use Ultra Disks, which are a type of high-performance disk storage offering. Enabling Ultra Disk compatibility enables VMs to take advantage of the advanced performance and capabilities provided by Ultra Disks, including low latency, high throughput, and consistent performance for demanding workloads such as databases, analytics, and high-performance computing.

**What is Availability set?**\ \ An availability set is a feature in Azure that helps ensure high availability and reliability of virtual machines (VMs) by distributing them across multiple physical hardware nodes within a datacenter. By placing VMs in separate fault domains and update domains within the availability set, Azure ensures that if one hardware node or update operation fails, the VMs remain available and operational. This helps minimize downtime and ensures that applications hosted on Azure VMs remain accessible even during hardware failures or planned maintenance events.

**What is fault domains in availability set?**\ \ Fault domains in an availability set are logical groupings of virtual machines (VMs) within Azure that are physically isolated from each other. These fault domains ensure that if a hardware failure or maintenance event occurs, only one fault domain is affected, while the other fault domains remain operational. Azure automatically distributes VMs within an availability set across multiple fault domains to maximize availability and minimize the impact of hardware failures on the hosted applications.

**What is update domains in availability set?**\ \ Update domains in an availability set are logical groupings of virtual machines (VMs) within Azure that define the order in which VMs undergo planned maintenance events, such as software updates or host reboots. Each update domain represents a group of VMs that can be updated independently, ensuring that not all VMs within the availability set are updated or rebooted simultaneously. By spreading VMs across multiple update domains, Azure helps ensure high availability of applications hosted on VMs by minimizing the risk of downtime due to maintenance operations.