Managed Disk
A block-level storage volume managed by Azure and attached to a virtual machine, available in Standard HDD, Standard SSD, Premium SSD, and Ultra Disk performance tiers, with Azure handling the underlying storage account.
Managed Disk
Managed Disks abstract away the storage account behind a VM's disk — you choose a performance tier and size, and Azure handles placement and redundancy.
Why It Matters in Production
Hotstar runs its encoding-farm VMs on Premium SSD managed disks for the high IOPS needed during live IPL transcoding, while archival VMs use Standard HDD to cut cost.
az disk create --resource-group hotstar-encoding-rg \ --name encoder-node-01-osdisk --size-gb 128 --sku Premium_LRSTipUse Ultra Disks only for latency-sensitive workloads like SQL Server transaction logs — most workloads don't need the extra IOPS.
Frequently Asked Questions
What's the practical difference between Premium SSD and Standard SSD managed disks?
Standard SSD is designed for workloads with consistent, moderate I/O — web servers, dev/test environments — offering better latency than Standard HDD at a lower cost than Premium. Premium SSD uses solid-state storage with guaranteed IOPS and throughput tied to disk size, making it the default choice for production database and transactional workloads. Ultra Disk sits above both, letting IOPS and throughput be tuned independently of capacity for the most latency-sensitive apps.
What's a common mistake when sizing managed disks for a production VM?
Under-provisioning disk size to save cost is a frequent trap, because Premium SSD performance (IOPS/throughput) scales with disk size tier, not just capacity — a small disk can bottleneck a VM that otherwise has plenty of compute headroom. Another gotcha: resizing a managed disk usually requires deallocating the VM first, so capacity planning up front avoids unplanned downtime during a later resize.