AZ-104
Deep Dive
Azure Backup provides managed backup for VMs, databases, blobs, files and more. AZ-104 evaluates backup policy configuration, restore options and the protections against accidental deletion.
Contents
Recovery Services Vault (RSV)
The original and most complete vault. Supports both Azure Backup AND Azure Site Recovery. Recommended for most scenarios.
Protects
Backup Vault
Newer vault, focused on modern PaaS. Does NOT support Azure Site Recovery. Uses the newer ARM API and supports newer workloads.
Protects
Vault configuration — critical options
Storage Replication Type
LRS (3 copies in the datacenter), ZRS (3 zones), GRS (replica in the paired region — default). Change it BEFORE configuring backups.
Cross Region Restore
With GRS: enabling it lets you restore in the paired region even if the primary is down. Requires GRS.
Soft Delete
Enabled by default for 14 days. Deleted backup data is retained for an additional 14 days before permanent deletion.
| Workload | Vault | Agent/Extension | Frequency | Max retention |
|---|---|---|---|---|
| Azure VM | RSV | VM Backup Extension (auto) | Daily / every 4h (Enhanced) | 9999 days |
| Azure SQL in VM | RSV | SQL Workload Extension | Every 15 min (log) / daily / weekly | 35 years |
| SAP HANA in VM | RSV | HANA Backint plugin | Every 15 min (log) / daily | 35 years |
| Azure Files | RSV | Native snapshot (agentless) | Daily / weekly | 200 snapshots |
| Azure Blobs | Backup Vault | Agentless (operational) | Continuous (operational) | 360 days |
| Azure Disks (managed) | Backup Vault | Agentless (snapshot) | Every hour minimum | 1 year |
| On-premises (files) | RSV | MARS Agent (manual) | 3 times/day | 99 years |
VM backup process
Recovery point tiers
Snapshot tier (instant restore)
Snapshots are retained locally (in the VM's resource group) for 1-5 days. Very fast restore because nothing needs to be transferred from the vault.
Vault tier (standard)
Data transferred to the vault for long-term retention (days, weeks, months, years depending on the policy).
Archive tier
For recovery points older than 6 months. Much cheaper storage. Slower restore (requires ~24h rehydration).
Consistency types in VM backup
Application-consistent: VSS quiescing — data and pending transactions completed. Clean state for restoration.
File-system consistent: snapshot of all disks simultaneously. File-system-level consistency, not open transactions.
Crash-consistent: the disk state at a single instant — as if the power had been cut. Used only if VSS fails.
Enhanced backup policy
Standard policy: backup once a day (overnight window).
Enhanced policy: backup every 4, 6, 8 or 12 hours — for VMs that change quickly and need a lower RPO.
Requires: VMs with Managed Disks. Limited compatibility with certain disk types.
A Backup Policy defines the backup schedule and retention rules. It is associated with resources when protection is configured. A policy can apply to multiple resources; a resource can only have one active policy.
Components of a policy
Schedule
When to run the backup. Daily (specific time) or Weekly (day of the week + time). Enhanced: every 4-12h.
Instant Restore
Local snapshot retention: 1-5 days. Higher = faster restore but more expensive.
Daily retention
How many daily recovery points to keep. Max 9999 days.
Weekly retention
One recovery point per week (which day). Max 5163 weeks.
Monthly retention
One recovery point per month (which day). Max 1188 months.
Yearly retention
One recovery point per year (which month). Max 99 years.
GFS — Grandfather-Father-Son
The most common retention model in Azure Backup. Combines daily, weekly, monthly and yearly retention to optimize cost vs. time coverage.
Create new VM
Creates a brand new VM from the recovery point. You can change the name, resource group, VNet and subnet. The original VM stays intact.
When to use
Restore to a prior state without deleting the current VM. Compare states.
Restore Disks
Restores the disks (VHD/Managed Disk) to a Storage Account or resource group. You can then attach them to an existing VM or manually create a new one.
When to use
Granular control over the restore process. Attach the restored disk to an existing VM.
Item-level restore (ILR)
Mounts the recovery point as a disk and browses the file system to recover individual files/folders without restoring the whole VM.
When to use
Recover an accidentally deleted file with no impact on the production VM.
Replace existing disk
Replaces the existing VM disk with the disk restored from the recovery point. The VM must be stopped.
When to use
Restore "in-place" on the same VM. The VM must not be running.
Cross Region Restore
Restore in the paired (secondary) region using the vault replicated via GRS. Requires CRR to be enabled on the vault.
When to use
The primary region is down. DR using Azure Backup (not ASR).
Cross Subscription Restore
Restore into a different subscription. Useful for multi-subscription environments where production and DR live in separate subscriptions.
When to use
Restore into a DR or test subscription without affecting the production subscription.
Soft Delete protects backup data against accidental or malicious deletion. When a backup item is deleted or protection is stopped and data is removed, the data is retained for an additional period (14 days for VMs) before permanent deletion.
Soft Delete behavior
Multi-User Authorization (MUA)
MUA requires approval from a second user (Resource Guard in another subscription) for critical destructive operations on the vault: disabling soft delete, stopping backup and deleting data, modifying retention policies.
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An administrator wants to recover a single file from a VM backup taken 3 days ago without creating a new VM or interrupting the current production VM. Which restore option should they use?
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