# Azure Disk Snapshot

> Azure disk snapshots bill per GB of stored data for as long as they exist, independent of any VM or disk. ZopNight discovers all snapshots in one subscription-wide Resource Graph query, links each to its source disk with age, and flags old or redundant snapshots for cleanup.

Source: https://zop.dev/integrations/azure/azure-snapshot
Updated: 2026-08-19

---

Disk snapshots are point-in-time copies of managed disks, billed per GB for as long as they exist. Snapshot sprawl from ad hoc backups quietly accumulates for years.

## A meter with no off switch and no expiry

A snapshot bills per GB of occupied storage from the moment it is taken until the moment it is deleted. Nothing about it ever pauses: the source VM can be deallocated, the source disk can be deleted, the project can end, and the snapshot keeps metering. Full snapshots pay for the complete copy, while incremental ones charge only for changed data, but either way the charge is open-ended. Because a single snapshot is small and cheap, no individual one ever looks worth deleting, which is precisely how subscriptions end up carrying hundreds of them.

## Subscription-wide discovery parented to source disks

ZopNight's snapshot enricher issues a single subscription-scoped Resource Graph query, deliberately not per-region, and classifies every result. Snapshots whose source disk still exists become individual azure-snapshot resources parented to that disk, carrying source-disk linkage and age; those whose disk is gone are routed to the separate orphaned-snapshot aggregate. Cost Management billing attributes storage spend, and recommendations flag old or redundant snapshots. A snapshot cannot be stopped or scheduled, so the entire savings lever is deletion of what no longer earns its keep.

## How snapshot sprawl actually happens

The accumulation follows familiar scripts: a manual snapshot taken before a risky change and never revisited once the change succeeded; automation that creates dailies but was never taught to prune; and pre-migration copies of disks that were migrated years ago. Each event adds a few GB that nobody owns afterwards.

## Listing every snapshot in the subscription

Azure portal → Snapshots shows all snapshots with size, creation time, and source. Sorting by Time created oldest-first is the quickest manual audit: anything predating the last few release cycles deserves a justification or a delete.