Azure Managed Disks
Azure managed disks are block-level storage volumes that are managed by Azure and used with Azure Virtual Machines. Managed disks are like a physical disk in an on-premises server but, virtualized.
In this lecture, the focus is on Azure Managed Disks, which are block-level storage volumes for Azure virtual machines (VMs) that are managed by Azure, eliminating the need for manual storage management. The lecture discusses the simplicity of creating these disks by specifying the size and type, and the process whereby Azure takes care of the rest.
The discourse continues with a detailed examination of the various disk types available in Azure, starting with Ultra Disks—high-performance storage suitable for data-intensive workloads—which cannot be used as OS disks and are provisioned empty. Premium Solid State Drives (SSDs) are presented as a step down in performance but still suitable for mission-critical production apps, with compatibility limited to certain VMs. The lecture introduces Premium SDD v2 disks, currently in preview, which boast sub-millisecond latencies and adjustable IOPS, throughput, and size for IO-intensive enterprise workloads.
The instructor then moves on to Standard SSDs, which offer consistent performance for lower IOPS workloads, suitable for lightly used enterprise apps and web servers. Conversely, Standard HDDs provide low-cost disk support for VMs with latency-tolerant workloads and are described with specific latency performance metrics.
A significant portion of the lecture underscores the reliability and availability of managed disks, designed for 99.999% availability by maintaining three replicas of the data. It also touches on the scalability of managed disks, with up to 50,000 VM disks of a particular type allowable within a single subscription and region.
Towards the end, the lecture delineates the three main disk roles: Data Disk, OS Disk, and Temporary Disk. Each has a specific function within the VM ecosystem, from storing application data to hosting the operating system and providing temporary storage for transient data. Special attention is given to the Temporary Disk, highlighting its volatile nature and the potential for data loss during maintenance events.
To wrap up, the instructor advises the importance of understanding the different types of managed disks and their roles—OS, data, and temporary—for exam preparation. This encapsulates the lecture’s comprehensive overview of Azure Managed Disks and their application within Azure VM environments.