Storage tiers
Azure storage services provide different storage tiers so that you can store your data objects in the most cost-effective and performant way that meets your needs. The tier you choose should be based on how frequently data is accessed, along with whether data can be moved between tiers at any time; you should also consider the data access/retrieval (rehydration) costs.
The three storage tiers that are available are as follows:
- Hot tier: Optimized for frequently accessed data; highest storage costs, lowest access costs.
- Cool tier: Optimized for infrequently accessed data that is stored for at least 30 days; lower storage costs, higher access costs.
- Archive tier: Optimized for rarely accessed data that is stored for at least 180 days; lowest storage costs, highest access costs, and data retrieval (rehydration) costs; data is offline and it will take several hours for the first byte to be accessible.
This section looked at storage tiers. In the next section, we will look at storage replication.
Storage replication
Microsoft provides redundancy of your data in Azure through several replication options, all of which we will look at in this section. However, note that under the shared responsibility model, you are responsible for ensuring your data is available and protected and that you select the most appropriate replication and protection model to meet your needs.
The following are the redundancy options that are available within a primary region, though some regions offer more replication types:
- Locally redundant storage (LRS): Provides three copies of your data, replicated synchronously within a single physical location in the primary region. This is the lowest cost option but also has the lowest availability and durability.
- Zone-redundant storage (ZRS): Provides synchronously replicated copies of your data across three availability zones in the primary region. This is a higher-cost option but it has the highest availability and durability within a region.
The following are the redundancy options that are available within a secondary region:
- Geo-redundant storage (GRS): Provides three copies of your data, replicated synchronously within a single physical location in the primary region; your data is also asynchronously replicated to a single physical location in the secondary region. This secondary region provides three copies of your data, replicated synchronously as LRS.
- Geo-zone-redundant storage (GZRS): Provides synchronously replicated copies of your data across three availability zones in the primary region; your data is also asynchronously replicated to a single physical location in the secondary region. This secondary region provides three copies of your data, replicated synchronously as LRS.
This section looked at storage replication. In the next section, we will look at data stores.
