> ## Documentation Index
> Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Container Blob Storage
> Azure Blob Storage offers scalable object storage with robust security, tiered pricing, and data management features for managing files in the cloud.
Azure Blob Storage provides a flat, internet-friendly namespace for managing files in the cloud. It’s the go-to solution for scalable object storage, offering robust security, tiered pricing, and rich data management features.
## Architecture and Namespace
Within an Azure Storage account, you organize data into *containers*—each holding an unlimited number of blobs (files). This flat namespace means:
* Containers cannot be nested, ensuring concise URLs (e.g., `https://.blob.core.windows.net//`).
* Each blob can be up to 4 TB in size.
* You can create as many containers as needed.
## Blob Types and Use Cases
Azure supports three blob types to optimize for different scenarios:
| Blob Type | Description | Common Use Case |
| ------------ | ---------------------------------------------------------------- | ------------------------------- |
| Block blobs | Efficient for uploading/downloading large files in blocks. | Images, videos, documents |
| Page blobs | Random read/write on fixed-size pages (512 B pages). | Virtual machine disks |
| Append blobs | Optimized for append-only operations; ideal for continuous logs. | Telemetry logging, audit trails |
## Access Tiers in Standard Storage Accounts
Optimize costs by selecting the right access tier:
| Tier | Storage Cost | Read/Write Cost | Best For |
| ---- | ------------ | --------------- | --------------------- |
| Hot | Higher | Lower | Frequently accessed |
| Cool | Lower | Higher | Infrequently accessed |
### Archive Tier
For long-term retention of rarely accessed data:
* **Archive**: Lowest storage cost, highest retrieval latency (up to 15 hours) and cost.
## Storage Account Options at a Glance
Choose from these account types and tiers:
* **Premium**: Low-latency, high-throughput workloads.
* **Standard Hot**: Frequently accessed data.
* **Standard Cool**: Infrequently accessed data.
* **Archive**: Long-term storage for rarely accessed files.
## Pricing and Retention Policies
Billing factors include:
* **Data stored** (GB/month)
* **Data operations** (ingress/egress)
Standard cool and archive tiers have minimum retention periods:
| Tier | Minimum Retention |
| ------- | ----------------- |
| Cool | 30 days |
| Archive | 180 days |
Early deletion in cool or archive tiers incurs an early deletion fee for any data removed before the minimum retention period.
## Automating Data Lifecycle with Policies
Use Azure Blob **Lifecycle Management** to transition blobs between tiers or delete stale data automatically based on rules (e.g., age, last modified).
```json theme={null}
{
"rules": [
{
"name": "move-to-cool",
"type": "Lifecycle",
"enabled": true,
"definition": {
"filters": { "blobTypes": ["blockBlob"] },
"actions": {
"baseBlob": { "tierToCool": { "daysAfterModificationGreaterThan": 30 } }
}
}
}
]
}
```
## Change Tracking with Blob Change Feed
Enable **Blob Change Feed** to record every change (create, update, delete) in a durable, replayable log. This supports:
* Point-in-time restores
* Auditing and compliance
* Data synchronization across accounts
## Links and References
* [Azure Blob Storage documentation](https://docs.microsoft.com/azure/storage/blobs/)
* [Lifecycle management overview](https://docs.microsoft.com/azure/storage/blobs/storage-lifecycle-management-concepts)
* [Blob Change Feed](https://docs.microsoft.com/azure/storage/blobs/storage-blob-change-feed)