The Azure Storage Blob service is for customers needing to store large sets of unstructured data. Because unstructured data is generally difficult to handle, the Azure Storage Blob service provides you with containers, an instrument for organizing the data.
Some facts about containers:
- The Azure Storage Blob service can use an indefinite count of containers.
- Each blob is assigned to one container.
- A container may contain an indefinite number of blobs. The only restriction is the capacity limit of the storage account.
Let's return to the subject of blobs. Three types of blobs are currently available:
- Block blobs
- Append blobs
- Page blobs
Block blobs are utilized for streaming and storing objects. They are best used for storing documents, media files, backups, and so on. Whereas block blobs are used for streaming and storing, append blobs fulfill the same task with the addition that they are optimized for append operations. Updating an append blob can only be done by adding a new block to the end. Append blobs' field of application consists of logging, in which data has to be written to the end of the blob. The third type of blob is the page blob. In most cases, page blobs are used to store VHD files for Azure IaaS VM solutions.
What else should I know about the Azure Storage Blob services?
When creating a blob storage account, you must set the Access-Tier attribute. Three types of access levels can be defined based on the data access pattern:
- Hot access tier: This level means that objects are kept in the storage account on a regular basis
- Cool access tier: This level indicates that objects in the storage account are less regularly retrieved
- Archive access tier: This level indicates that objects in the storage account are rarely accessed but must be stored for a long period of time to meet business continuity and compliance requirements (for example, medical records)
It is possible to switch, at any time, between these levels when a change in the usage pattern of the data makes this necessary.