Resource locks (delete, read-only) in Azure - Step-by-Step Execution

Process Flow - Resource locks (delete, read-only)

Start

↓

Apply Lock

↓

Lock Type?

Delete Lock→Block Delete Actions

↓

Block Delete & Modify Actions

↓

Try Operation

↓

Is Operation Allowed?

Yes→Operation Succeeds

↓

Operation Fails with Lock Error

↓

End

This flow shows how applying a resource lock in Azure controls what operations are allowed or blocked on that resource.

Execution Sample

Azure

az lock create --name Lock1 --lock-type CanNotDelete --resource-group MyGroup --resource MyVM --resource-type Microsoft.Compute/virtualMachines
az vm delete --name MyVM --resource-group MyGroup
az lock create --name Lock2 --lock-type ReadOnly --resource-group MyGroup --resource MyVM --resource-type Microsoft.Compute/virtualMachines
az vm update --name MyVM --resource-group MyGroup --set tags.env=prod

This sequence applies a delete lock, tries to delete a VM (blocked), then applies a read-only lock and tries to update the VM (blocked).

Process Table

Step	Action	Lock State	Operation Attempted	Allowed?	Result
1	Create Delete Lock on MyVM	Delete Lock	None	N/A	Lock applied successfully
2	Attempt to Delete MyVM	Delete Lock	Delete VM	No	Operation blocked: delete lock prevents deletion
3	Create Read-Only Lock on MyVM	Read-Only Lock	None	N/A	Lock applied successfully
4	Attempt to Update MyVM Tags	Read-Only Lock	Update VM	No	Operation blocked: read-only lock prevents modification
5	Attempt to Read MyVM Info	Read-Only Lock	Read VM	Yes	Operation succeeds: read allowed under read-only lock
6	Remove Locks	No Lock	None	N/A	Locks removed, operations allowed
7	Attempt to Delete MyVM	No Lock	Delete VM	Yes	Operation succeeds: no lock present

💡 Locks block operations based on type; delete locks block deletion, read-only locks block deletion and modification but allow reading.

Status Tracker

Variable	Start	After Step 1	After Step 3	After Step 6	Final
Lock State	None	Delete Lock	Read-Only Lock	No Lock	No Lock
Operation Allowed	N/A	No (Delete)	No (Update)	N/A	Yes (Delete)

Key Moments - 3 Insights

Why does the delete operation fail at step 2 but reading the VM info at step 5 succeeds?

Because the delete lock blocks delete actions but allows read actions. At step 5, the read-only lock allows reading, so the operation succeeds (see execution_table rows 2 and 5).

What is the difference between a delete lock and a read-only lock?

A delete lock only blocks deletion, while a read-only lock blocks deletion and any modification but allows reading (see execution_table steps 1 and 3).

What happens after locks are removed at step 6?

All operations are allowed again, so deleting the VM at step 7 succeeds (see execution_table rows 6 and 7).

Visual Quiz - 3 Questions

Look at the execution table, what is the lock state after step 3?

A Read-Only Lock

B Delete Lock

C No Lock

D Unknown

💡 Hint

Check the 'Lock State' column at step 3 in the execution_table.

At which step does the delete operation become allowed?

A Step 2

B Step 7

C Step 5

D Step 4

💡 Hint

Look at the 'Operation Attempted' and 'Allowed?' columns for delete operations in the execution_table.

If the read-only lock was not applied at step 3, what would happen at step 4 when updating the VM?

A Update would be blocked

B Delete would be blocked

C Update would succeed

D Read would be blocked

💡 Hint

Refer to the 'Lock State' and 'Allowed?' columns at step 4 and consider absence of read-only lock.

Concept Snapshot

Resource locks in Azure protect resources from unwanted changes.
Delete lock blocks only delete operations.
Read-only lock blocks delete and modify operations but allows reading.
Locks help prevent accidental or unauthorized changes.
Locks can be applied or removed anytime via Azure CLI or portal.

Full Transcript

Resource locks in Azure help protect resources by blocking certain operations. There are two main types: delete locks and read-only locks. A delete lock prevents the resource from being deleted but allows other changes. A read-only lock prevents deletion and any modifications but still allows reading the resource. When a lock is applied, operations that are blocked will fail with an error. Removing the lock restores full access. This trace showed applying a delete lock, trying to delete the resource (blocked), then applying a read-only lock and trying to update the resource (blocked), and finally removing locks to allow deletion. Understanding these locks helps keep resources safe from accidental or unauthorized changes.